My home hifi cost far too much, so I'd probably be considered an audiophile, but I have the base system in my Cayman. It's a very loud metal box, so no point spending more on upgrading in my view.I don't have Bose or Burmeister, so I can't comment directly on how awesome those options may be.
I do have the base system, and for me it is entirely adequate, I don't need anything more. The reason for me is that these cars are not the most quiet cabins to begin with (lots of road and engine noise - which is not a bad thing) and such a small space - the base system works plenty good enough for me.
The only thing potentially lacking is a big bass response if you really want to bump some rap music. Again, plenty good enough for me, but I am sure that real audiophiles would disagree (maybe my hearing is not as discerning after going to so many live shows in my life).
+1I doubt I'll even turn the radio/sound system on.
I am not especially a Bose fan either. (A confession - I spent 10 years as an engineer at Lexicon, a Harman company and thus a Bose competitor.) However the off-the lot car I selected had Bose and I'm satisfied with it. The Cayman environment is too noisy to experience good audio reproduction but the Bose system does okay. I don't push it because I don't want to subject my ears to high volume just to hear subtlety while driving.... I'm not a Bose fan though...
I then landed up buying a car that had Bose fitted ... and have set it up so that it bypasses their surround sound processing