BMW Performance Springs... not for 335i, 335xi...
there aren't much options for E90-335xi-09.... I checked daily on the web, BMW specialist....
Seems, Dinan S-pack, or suspension system is the $$ way but not the muffler, many feel like its like made in China quality!!
KW-V3, UCC front and rear sway bars, better way then Dinan's value!