Some people believe this bullshit though. My mate with a Merc said about this kind of thing on ebay the other day, and how he was going to get one. He didn't understand that it's a load of bollox and will end up f**king your car.
I find it funny the way that they say chipping your car makes normal driving worse?!?! That's just bollox, everytime I've chipped a car it's got better, as has the mpg.