I have a 2002 BMW 330 Ci Convertible. Congrats on a great car. I love mine. The sound system is okay. It's better than the standard factory. It by no means sounds like anything out of a 7 series, but it sounds a helluva lot better than ANYTHING out of a Z3. Your base will have a little thump, but you aren't going to sound like a thugsta. My dad drives the X5
4.6. It's got a GREAT sound system in it. Dunno if it's factory or not, but it beats the hell out of my 3. But as far as refinement goes, you will be more than impressed with your harman/kardon 3 series.
"Bangkok Tower, United 890 Heavy. Bangkok Tower, United 890 Heavy.....Okay, fine, we'll just turn 190 and Visual Our Way