It was from the early naughties and was presented by Jason Barlow and Dominic Littlewood. The idea was that each week a person would have the wrong car one they didn't like or want anymore normally something like a rusty VW Polo and they would receive help to get the right car normally something newer and generally better. They would test drive various cars and the person would wear a secret ear piece when negotiating with the dealer and Dominic would be telling them what to say his catch phrase being "get the mats and flaps".
I think the show was a vehicle for Jason Barlow as Top Gear had been axed (he was then the main presenter) and he was on contract so they needed a show for him. I also think this was the first TV job for Dominic Littlewood who was an ex car dealer.