Originally Posted by crazyinp
Who is the US vendor for Supersprint?
You can buy directly from the company or choose one of the dealers:
Anyway, if you can't remove any DPF / CAT from the 335d, go with straight pipes, possibly bigger as they'll give you a deeper sound, but don't expect it to sounds like a petrol.
Supersprint can easily make you some pipe-only rear muffler with the same endpipes (dual or quad) as their racing ones.