E90/E91/E92/E93 (2006 - 2013)
I have a BMW e92 320d, and I'm looking to upgrade the sound system.
At the moment, I think it's just the base system, with underseat subs. But it sounds rubbish, with no real bass.
I'm wanting to upgrade the audio, ideally under £500. The main thing I'm looking to get out this...