My buddy got a used CLS63 and wanted to do some upgrades. I told him what I had on my E and he decided to do the same. After he did the upgrades his car makes much more body noise when going into a driveway than before. That didn't change when I installed my pipes and I just assumed he was losing his mind.

I called the place that I bought my downpipes from and asked if they ever heard of anything like this, all he did was install a set of downpipes. I found out the answer....the crossmember was removed. My place told me that the cross member does not fit back correctly once downpipes are installed so everyone leaves it out and the body twists a lot after that.

They told me that the downpipes that I bought are the only ones that allow the cross member to still fit correctly and that is why my car doesn't make those sounds. He said that my friends cross member can probably be reinstalled using spacers but it will still be somewhat noisy like that, but it may be better.

My friend is pretty disappointed considering he bought the most expensive set of pipes on the market only to find out that they are an inferior product. I'm sure someone is going to get a deal on a used set of downpipes soon.

 

Tell your friend to chill .
I had the same issue and I had spacers made for the cross bar and there is no more rattling issue. Very easy mod.
Cost was $50 installed.

 

My Dps were custom made but have the same design as pretty much all of the ones out there. They are 3" piping though, and they cleared the crossmember. Sorry to hear bout your friend.

Aloha,
Will