I'm brand new to the BMW world, just purchased a 2009 335i E92. I have done a lot of research through forums and seem to get different answers everywhere i turn. Here is my issue. I am unhappy with the factory audio system and was wondering if anyone can shed some light on what they have done or seen as far as successful upgrades. I have the base or for the 335i the hifi system. I've heard that the jl xd600/6 can be installed to run in place of the oem amp, My only concern is would putting an aftermarket amp and speakers in be as good an upgrade as going with bsw speaker upgrade and then just wait for there amp to come out. I would appreciate any help i can get.