A whopping 14 per cent of those polled in a survey said they’d experienced either ‘erotic touching’, ‘heavy petting’ or full blown sex while actually driving or as a passenger on the open road.
Meanwhile almost half - 49 per cent - had turned-off the engine for sex acts in a stationary car.
And Wales was found to be the car sex capital of the UK, with 54 per cent of respondents having indulged in either heavy petting or full sex in their parked motor.
Leading motoring expert James O'Malley says the stats were ‘surprising’ - for all the wrong reasons.
Mr O’Malley, director of vehicle leasing firm Select Car Leasing, who conducted the research, said: “We know cars have long been linked with romance and passion here in the UK.
“But we were surprised, to say the least, that so many respondents had engaged in sexual activity while actually on the move.
“Attending to a lover is clearly a major distraction for a driver - and a real danger to other road users.”
The research, commissioned by leading polling firm OnePoll, quizzed 1,200 Brits aged between 18 and 65 years old.
Overall, a fifth - 19 per cent - admitted full intercourse in a stationary car.
Although there is no specific law against having sex and driving at the same time, those caught in a clinch risk being charged with ‘dangerous driving’.
Dangerous driving can see you given an unlimited fine, a hefty driving ban and even up to two years in prison.
But, surprisingly, sex in cars seems to be going out of fashion among Britain’s youth.
Just 12 per cent of those aged 18-24 said they’d had sex in a stationary car - compared to 19 per cent of those aged 35-44.
Meanwhile the most likely to have romped in a vehicle is those aged 55-64 years old - with 22 per cent in that age bracket having done so, suggesting layby romps could well be a habit of a bygone era.
Those in Wales lead the way when it comes to car seat fumbles - but the North East of England is runner up when it comes to road romps.
A massive 38 per cent of respondents there said they’d enjoyed heavy petting or full sex in a stationary car, while the North West of England was third placed with 35 per cent.
When it comes to full sex in a moving car, 2 per cent of respondents had risked doing it on the road, while 12 per cent had enjoyed either heavy petting or erotic touching in a moving car.
The findings come after an academic study suggested one of the results of new driverless cars would be an explosion in people getting intimate on the go.
An article – penned by Debbie Hopkins from the University of Oxford and Scott Cohen from the University of Surrey – claimed automotive vehicles would provide an irresistible venue for people wanting a cheeky bonk away from home.
“While [driverless cars] will likely be monitored to deter passengers having sex or using drugs in them,” they wrote, “such surveillance may be rapidly overcome, disabled or removed.”
They said the technology meant it was “just a small leap to imagine Amsterdam’s Red Light District ‘on the move’.”
And other studies have also examined car sex habits.
In 2016, the University of South Dakota surveyed 700 males and female students, with an average age of 20 years old.
Researchers found 61 per cent of men and 59.5 per cent of women reported they had engaged in sex while parked.
Of these, 14% lost their virginity in a parked car, and the ‘risk of being caught’ was ‘primarily a positive sexual and romantic experience for both men and women.’
Psychologist and study leader Dr. Cindy Struckman-Johnson said: “Sex and cars have gone together since the car was invented.”
Established in 2004, Select Car Leasing is one of the UK's largest independent specialists for car and van leasing.