I bought a 5 year old Mercedes C220 CDi Avantgard a few months ago and had a number of problems with it.
The latest one I've had is that I've discovered that a section of the exhaust has been removed and replaced with another piece of exhaust pipe.

The section removed is either a Catalytic convertor, a Particulate remover or the middle silencer piece. The section removed is after the splitter pipe about 1/3 along the car.

The company I bought it from (A dealership - but not a Mercedes one! - but can't state which one in case I have to take them to court!!) state that as it wasn't leaking at the time and the catalytic convertor (they recon it is this) is not required to be fitted by law to diesel cars for UK MOT's and are refusing to do anything about it.

I have spoken to trading standards who confirm that not staing this fact at purchase means it is an omission in their advert at time of sale and that they are obliged to do it, but will likely mean I'll have to go to court - can anyone shed light on what piece has actually been removed, wether it is required for an MOT, and what effect on the engine performance this missing piece would have.

Whilst this will be a useful start, if anyone can point me in the right direction for a contact at Mercedes who can get me the official confirmation (in case it does go to court) as I have got no reply from the normal Mercedes web page.

Many thanks for any assistance anyone can offer in this matter, I'm getting to the point where I am ready to sell the car on and get something else..