Hi, I just purchased a carbon fibre rear diffuser for a 335i exhaust conversion and im looking to see if anyone has done this before to give me an idea.
What id like to know is can this conversion be done using the existing rear box or can the box be done away with as with the diesel coupes???
If i can do away with the box does it make the car too noisey and mess up the emmissions for mot?
Any help or thoughts welcome