Need help planning DIY audio setup for Audi A4 '13 or fabrication shop in SE Michigan
 

New to the forums, so any help would be much appreciated. I recently got a 2013 Audi A4 2.0T with the premium plus package, and it has the base stereo rather than the upgraded bang and olufsen. My previous Audi (A6 2.8L 1998) had Bose and sounded a million times better than my current Audi, and I'm extremely unimpressed/unhappy and need to upgrade the stereo. I want to keep the stock look. I'm not looking to shake the entire neighborhood or cause an earthquake, I want a high quality sound system with clear/crisp sound across both treble/bass. Options include:

1) DIY project with aftermarket speakers/amp/sub (has to sound at least as good as Bose)
2) DIY project attempting to retrofit a Bose system from parts on ebay (though Bose uses 2 ohm speakers, and I think mine are 4 ohms at least)
3) Going to a place in southeast Michigan or nearby for a custom job from a shop. I'd like recommendations of places regardless just to have all the options on the table

My budget is ideally less than $1500, max $2000. As an example, search for part number 8K0 035 411 (back left main door speaker) and you'll see the terrible plastic housing, paper cone material, and tiny magnet. My current stereo has a main speaker and tweeter per door (total 4 tweeters, 4 main door speakers), two lateral dashboard speakers, one center dashboard speaker, two rear speakers, and a subwoofer.