Hi, Am new to this so first of all, hi all!! I'm hoping some of you Merc boffins may be able to help. I recently bought a Merc 2000 plate A160. Usually when buying a car I'm very meticulous but was having an off day and have been stung by not doing the correct checks. Firstly I've recently found out that the car is a Cat D having been shown a fake hpi report (now i know why they couldn't find it when car was handed over) Secondly, I stupidly did all the checks but never actually test drove the car (i know, I know - stupid). I checked all around, engine, fluids and gearchanges while stationary and all seemed well. Drove the car home and noticed a very bad clunk when changing down from 2 to 1. It's hardly noticeable if I have stopped the car before change down, but if the car is moving, it's an immense clunk. I'm hoping someone will tell me that the gearbox hasn't gone and it's a simple fix (I'm no mechanic) but am guessing it's a new gearbox job. Any opinions gratefully received, along with potential costs. Thanks all! Oh can I also add that the V5 says the car is an auto, so clearly it's been changed over at some point. Is this legal?