Despite Government consultation on ways to control the wheel clamping industry, the amount of people licensed to carry out such enforcement has actually increased.
And parking in the wrong place - even if just for a few minutes - could lead to unwary drivers finding any money they may have saved during the winter sales ending up in the hands of unscrupulous clampers.
There are currently some 2,100 individuals licensed to clamp, according to official figures.
The number is up from 1,200 in March 2008 and 1,900 in April 2009, when the Home Office launched its vehicle immobilisation consultation.
The RAC Foundation director, Professor Stephen Glaister, said: "There will be little festive cheer for bargain hunters if they put a wheel wrong when it comes to parking.
"The figures reveal more and more people are becoming clampers because the business is so lucrative and the law surrounding it so lax.
"With charges for being clamped and towed often running into several hundred pounds, cowboy clampers will be out in force during the sales, on the lookout for motorists who leave their car in the wrong place even for a few minutes. The huge rise in licence holders proves the Government needs to act quickly. It has promised a cap on fees, an appeals service and a binding code of conduct. In 2010 it needs to deliver."
The RAC Foundation is urging drivers to be extra careful over the festive period and to check parking arrangements before they head for the shops, and to consider options like park and ride.
© Press Association 2009