Originally Posted by OOOSQ
Speaker size does not vary from what I understand. Biggest difference is speakers and amps themselves along with tweeters located in the front pillars.
From what I can tell, and speaking to a local installer, the wiring is NOT in place. Apparently a lot of the euro manufacturers have done this for a while to save money - also explains why you can't dealer upgrade them.
Also, I poked my head in the hole where the amp would be and there are no tell-tale dangling connectors sadly.
I guess you can by the door trim that has the tweeter cutouts and fill with your own choice, but you'd need to do the wiring yourself.
It's a pro-job for me I think - the installer I spoke to recommended replacing the standard 4" units with Focal's, but said there would still be no midbass.