this was not for a boombox type of system and even the subs are not very boomy and extremely loud - they were there to complement the front speakers and actually just add the lower end of the frequency spectrum. even in my previous system which had a JBL W15GTI 15" subwoofer i used to play the sub very softly .... my friends used to tell me i was wasting a sub cos they could not hear it - but i could ..... it was more important to me that bass guitars sounded like bass guitars and kick drums sounded like kick drums and tom drums had musical impact .... rather than all condensing into one huge mushy boomy sound that assaulted your ears. hence i always pay more attention to the front speakers and how they are positioned - the sound systems in my car generally have a decent soundstage and image pretty well - and they were more geared toward being an audiophile setup instead of a basshead setup even with the subs being present.
I see the new premium model Audis come with Dynaudio systems.
Tom , I always had good service from Mark Chernotsky of Loud and Clear in CT/blaauwberg . Not sure if they still are around.All my cars (2 Corvettes and a Camaro) have OEM BOSE active speaker systems , pretty heavily weighted in the bass , they sound okish..... However all my cars are also V8's with fairly loudish unrestricted exhaust systems so you need some serious emphasis to hear bass over the engine/exhaust when the car is moving.V8 rumble and roar when you got the pedal to the metal is way more satisfying then car sound IMO.I drive about 15km a day tho , so mainly just listen to the radio anyway so whatever is in the car is ok for me.