But the man with a ready quip for nearly every occasion admits that one of his charitable roles is his hardest ever sell.
In 2016 he was appointed RoadSmart Mature Drivers Ambassador for the Institute of Advanced Motorists, but he says older drivers view him with some suspicion.
"Our aim is to help more mature drivers cope better with modern traffic conditions but many of those drivers feel that if they take the review it could result in us taking the keys of the cars away from them if they don't come up to scratch," he says. "They don't worry about being criticised, but of what they think might happen."
The Mature Drivers Assessment is a one-hour observation but there is no pass or fail. The driver is given a written review at the end of it and that can help them judge if their driving days are coming to an end or not.
But he is diplomatic when asked about the recent accident involving the 95-year-old Duke of Edinburgh and the subsequent publicity which questioned whether he should still be driving at that age.
"I wasn't there so I cannot comment on who was at fault or if anyone was," he says.
"What I know is that as one gets older reflexes get slower, eyesight can deteriorate and there can be the onset of dementia or Alzheimer's. I feel sorry for the duke because he got a very bad Press over the incident based on little hard evidence."
Paddy has taken the advanced test and, naturally, did very well in it and is now studying for his Masters Test.
"If I don't pass it I'm not going to tell anyone that I took it," he says jokingly.
He is passionate about the charity's work in improving driving standards and when his granddaughter passed her driving test just over a week ago on her 18th birthday he bought her an entry into the advanced test as a present.
Two of his own three children, Patrick and William, have taken and passed the IAM advanced test and William, whose test was for a motorcycle, said it saved his life twice. His sister Katie is due to take her advanced test shortly.
As president of the British Racing Drivers' Club, which owns the Silverstone circuit, Paddy invited a number of young rising stars in the motor racing world to take IAM assessment tests.
"The young drivers can have a bad image of tearing around at high speed away from the track and having too much money to spend but the examiners and instructors were delighted with the way they performed when they took their tests," he says.
This all seems very serious business for a man whose fun-loving personality helped to make him a household name during his rallying days.
His most memorable triumph came in 1964 when he and co-driver Henry Liddon won the famed Monte Carlo Rally - the only all-UK crew ever to win the race, although Belfast man Ronnie Adams had won it some years earlier. It was a victory which made Paddy and the Mini famous.
He set off from Minsk, now in Belarus but then part of the Soviet Union, in mid-winter. It was so cold that the cars had to be towed around the city square by tractors to get them started. The locals, having never seen a Mini car before, thought that was how they had to be started.
Paddy had brought several piles of ladies nylon stockings with him - "no, they were not for me to wear" - and swapped them with the chef of the hotel they had stayed in for a giant tin of Beluga No 1 caviar, which he intended to sell to the chef of a posh hotel in Monte Carlo. "The caviar would have sold for more money than I would have got for winning the rally," he explains.
As it happened Paddy and his many friends - including famed Formula One driver Juan Manuel Fangio, Stuart Turner, manager of the BMC team, and Mini designer Alex Issigonis - ended up eating the caviar washed down with Champagne and vodka after it was confirmed he had won the race.
Paddy received a congratulations telegram from The Beatles and the Prime Ministers of both Northern Ireland and the UK, as well as being presented with the winner's cup by Princess Grace (a few years ago on the 50th anniversary of his victory he brought the cup back to Monte Carlo to show to her son) and appearing on the primetime TV show Sunday Night At The London Palladium hosted by Bruce Forsyth before millions of viewers.
Of course, the rally didn't run entirely smoothly for Paddy and his co-driver Liddon.
In a small French village Paddy inadvertently drove the wrong way up a one-way street and was stopped by a gendarme who threatened to book him. That would have resulted in disqualification but Paddy told the bemused policeman that he had resigned from the race and was hurrying home because his mother had died. Thus history was made with the aid of a porky.
A couple of years later he was controversially disqualified along with two other Mini drivers as the trio were poised to take the first three places in the rally because of some technical infringement with his headlights.
But while he was always determined to win, it was not a win-at-all-costs mentality.
Famously, he was lying in second place and about to win the London-Sydney Marathon Rally in 1968 when the driver in front crashed head-on with another vehicle on what was supposed to be a closed section of road.
Paddy and co-driver Alex Poole leapt out of their car and helped rescue the injured driver before the crashed vehicles burst into flames. Driving was in his blood. At the age of nine a clergyman friend of his parents left Paddy his invalid carriage in his will and it was in it that the future rally driver first learned the rudiments of car control.
Born in Windsor Avenue in Belfast, which runs between the Malone and Lisburn Roads, Paddy and his family later moved to Whitehouse on the northern outskirts of the city.
A Catholic, he was educated first of all at a convent school at Fortwilliam, then St Malachy's College and later the prestigious Clongowes Wood College in Co Kildare run by the Jesuits.
It was a mix that was not destined to work and Paddy was asked to leave after falling out with the principal.
He finished secondary education at Garvey College, a crammer school in Belfast, and then went to Trinity College Dublin, at the time regarded as a Protestant university. Paddy recalls: "Because I didn't get permission from the Catholic Church to go to Trinity, I was automatically excommunicated (a 100-year-old ban on Catholics going to Trinity was not lifted until 1970).
"That gave me the freedom to kiss girls without committing a mortal sin," he quips.
Since then he and the Catholic Church have had something of a nodding acquaintance - "I married an English Protestant, Jennifer, who is nine years younger than me, when I moved to England and our family is a mixture of religions and none," he says.
Nowadays he is a fervent supporter of integrated education in Northern Ireland and blames the clergy for insisting on retaining the segregated system of schools.
Paddy now lives in a small village in Buckinghamshire close to celebrity baker Mary Berry - "a lovely woman" - but comes back home or various charitable events and to the recent Belfast Telegraph Sports Awards.
He recalls driving a Mini - a replica of the one in which he won the Monte Carlo race - to the Titanic Quarter in Belfast and pulling up outside a hotel that was hosting a wedding.
"Obviously several of the guests were attracted to the vehicle in its racing livery and I noticed a couple of more mature gentlemen studying it closely. One of them said: 'That must have been the car in which that guy from here won the Monte Carlo Rally. I wonder when he died'."
Paddy is quick to reassure his fans that he has no intention of dying any time soon. "I still work as a salesman - that is what I have done all my life - and carry out presentations on behalf of the IAM. I get the message across about safer driving but I also try to make the presentations more entertaining by telling them some of the stories from my days rallying," he says.
In the early 1970s he was involved in importing Toyota cars into Northern Ireland to the Neville Johnson garages. Neville Johnson was his mechanic, but tragically died while taking part in the Spelga Hill Climb in the Mournes in the early part of the decade.
Paddy also developed his own brand of car accessories and is a brand ambassador for BMW, the motor company that has resurrected the Mini.
And that could turn Paddy into a film icon for there are plans to make a movie about the Mini and his famous Monte Carlo Rally win. It could have another Northern Ireland connection, as the people behind the movie want Co Down-born Hollywood star Jamie Dornan to play Paddy. It is casting which would delight the effervescent Hopkirk immensely and bring his skills to the attention of a new generation.
"I don't think there is the same public interest in rallying now as in my day. Then the idea of people racing 2,500 miles through ice and snow grabbed people's attention. It seemed like an adventure," he says.
Meanwhile, he will continue his safer driving crusade. "One thing that really annoys me is that the two speed awareness courses which I have attended for those caught speeding never mention what I consider to be the most important aspect of driving: control of the car. I also feel it is important to stress the two-second rule - the distance you should stay behind another car on the motorway. Motorways are safe but most accidents on them involve someone driving into the rear of the vehicle in front," he says.
"I may be 85 going on 86 but with my background I feel I can control my car well. I have never had an accident. That is something that you don't necessarily lose as you get older. But I have also learned from IAM tests to use my mirrors more. That is something that you get a bit complacent about as you get older. London bus drivers are fantastic at using their mirrors and we could all learn from them."
He would also like to see the insurance companies encourage more drivers to take advanced assessments like those given by the IAM by reducing premiums to participants.
"However, insurance companies are like bookies, they base their premiums on statistics on accidents, ages and payouts. Unfortunately we don't have enough statistics on how our tests help people drive more safely, but maybe one day the insurance companies will see our point of view," he says.
Married for 52 years, Paddy, who received an MBE in the New Year Honours List in 2016 for his charitable work, is keen to praise Jennifer for her assistance over the years.
"She has done a fantastic job in giving our three children a balanced view of life and has been very supportive of me in all I have done," he adds.
Looking and sounding remarkably spry for his age, he reveals that he walks his dogs three or four miles every day and also plays tennis on a Sunday.
Still no sign of slowing down.