Close to 12 million motorists - or 31% of Britons on the road - admit to parking in spaces they should not have over the last 12 months, according to new research from the insurer Churchill.
And many of those who parked on double yellow lines, in disabled bays or in spaces reserved for mothers with babies, have got away without being fined.
Parking fines worth a massive £80 million have been handed out in the last year, with the average fine coming in at £45. But that means just 1.8 million of the 12 million ignoring the parking rules have been caught and penalised.
Fines are not the only risk drivers take when parking in spaces reserved for others, though.
Nearly one in ten motorists who have done so have returned to find their car damaged or have been told off by a passer by.
Steve Barrett, head of car insurance at Churchill, said: "Bays dedicated to disabled drivers or parents with children are there to make life easier for those who may struggle with accessibility and parking in these bays when not eligible is extremely selfish.
"With fines averaging £45, that five-minute rush into a shop for a newspaper could also end up being very costly."
The most common prohibited places people park are on double yellow (8%) and single yellow lines (7%). But disabled bays are also regularly used by people who have no need for them.
More than 2 million - or 6% of - drivers admit to parking in disabled bays, with the most popular excuse being that "it was only for a short time so I didn't think it would matter".
Mother and baby spaces are also fair game for many motorists. Some 5% of drivers have used a space of this nature in the last 12 months despite not having a baby with them.
Some drivers even admit to parking in both disabled bays and mother and baby spaces simply because they were the most convenient spots.
However, about eight in 10 UK adults believe those parking in reserved spaces of this kind should receive points on their licence if they get caught.