Upgrade Recommendations

[el_duderino]

Happy to help.

OK, without rear speakers, that's a big plus for your sound quality.

I'd use a Zapco 360.4 amp to run the speakers.

For a sub, of the lines you mention, the only one making any subs of consequence is Focal, and I don't have any experience with them.

OK, what I would do is use a Dynaudio System 240 GT in the front. The MW160GT woofers fit with a hiar of trimming into the BMW speaker spacer frames. The tweeters fit in the top of the dash very well, and they play a lot of upper midrange so you get a very good front stage. Don't listen to any stuff about how the mid shouldn't be too far from the tweeter. Theoretically that's true, but they also shouldnt be too far apart, and the lesser evil is to have a tweeter like the Dyne playing lots of vocals as far forward as possible filling the center. (Don't do this with Focal - tweets aren't going to perform the same way.)

Then I'd use a good 10" sub. They probably have someone else besides those for subs, but I know Focal makes some, I just don't know if you can get one around $200 that's any good. The Dyne subs don't play loud enough.

You should be able to get all that installed for about $2500 - depending on the labor.

What shop are you working with, and where? I'd be happy to talk them through OEM HU integration if they aren't conversant with it (and if they try to sell you on some kind of LOC, I really want to talk to them).