93 CS Q Wagon

[Eric Billing <eric.billing@heimdall.sdrc.com>]

I just bought a 93 100 CS Quattro Wagon with 25K miles. Decided that this was a much better solution to our growing family requirements than a sport ute or mini-van any day. My prior cars have all been Hondas and hope that this Audi can perform as well in the reliability category.

We're taking it to the dealer tomorrow to fix the "low washer fluid" idiot light, and to adjust the rear passenger door. Other problems include:

a) humming from rear (sounds like a fog horn in the distance)
b) stereo ... bass/treble seem wimpy for a car with a MSRP of $45K

Actually, I would appreciate any suggestions regarding stereo/CD upgrades. Anybody with experiances or references to places (I saw a reference to Crutchfield in one of the postings)? 
 
Other questions:

a) Oil change at 3000 or 7500??? I typically take my Honda to the corner Rapid Oil Change, is this a good idea?
b) The manual reccommends Premium gas... Any comments?

Thanks for any information.

Eric Billing
Eagan, MN
'93 100 CS Quattro Wagon (is there any official abbreviation for this. I want to make sure I'm as hip as the rest of you)