Back in January I started looking for a new car to replace my Acura Integra. It ultimately came down to the BMW 328Ci and Audi A4 2.8. I liked the more aggressive styling of the BMW 3-series but I couldn't justify the ~$38,000 price tag for the 328Ci (about $5k more for essentially 20 more horsepower vs. the 323Ci), so in the ultimate feat of rationalization I opted for the Audi S4 which was $2k more than the 328Ci, with the added benefit of 60 more horsepower, full time 4 wheel drive, and an extra 2 doors. ;-)
I ended up ordering a 2001 model at the end of March and it arrived at the dealer at the end of June. The major differences between the 2000 and 2001 models are: 1) $1k higher sticker price, 2) addition of ESP (electronic stability program), 3) Sport package became an added-cost option, and 4) longer warranty (4yr/50k mi). Be prepared for a wait if you plan on purchasing the S4 since it's a limited production car, especially in California.
I've had my 2001 S4 for about 1700 miles now, and I've loved every single mile of it. It's metallic silver with the onyx (black) interior, with the premium package (aka convenience package on the 2000 model) and Bose audio system. I opted to not get the 6-disc changer option since the OEM unit (Panasonic) can be had for $279 aftermarket vs. $650 installed with the car.
Engine/Performance
This car is a pleasure to drive. It's got incredible torque at low RPM's (258 lb/ft @ 1850-3600 rpm) so acceleration is effortless (and downright wicked if you floor it). It took a while for me to get used to the car's power as I was unintentionally launching like a rocket at green lights since I was used to the engine of my former (torque-weak) Acura Integra. Also, the car is very composed at highway speeds, so much so that I often don't realize that I was going 80+ mph when I thought I was going 60 since the cabin is very quiet and composed.
The six-speed took a little getting used to since the reverse gear is next to 1-2 (you push down, then left past 1-2, then up)...whereas on my Integra it was down from 5th gear. The throws are much longer as well (feels like you'll be elbowing people in the back seat), which is the only real driveability drawback that I see in this otherwise amazing car. An aftermarket short-shifter is definitely on the upgrade list.
The car is after all a 4 door sedan, so it's not nearly as tossable as my old Integra. There is more lean that I would like when i toss the car from side to side, but it's pretty taut for a stock suspension. Regardless, I feel it's got a good balance between performance and comfort. I've autocrossed the car once, and it definitely needs a stiffer and lower suspension for these type of events, but for everyday driving it's a good compromise.
Oh yeah, there is quite a lively aftermarket for the S4...there are at least 4 aftermarket tuners that you can go to for a new ECU which will easily bump your horsepower in the 310 hp range (stock is 250hp) and torque into the 360 ft/lbs range (stock is 258 ft/lbs) for about $500-600. So if you ever tire of the stock 250hp engine, you've got options ;)
Interior
The front seats are comfortable and I never felt fatigued from the seats during extended driving. I wish the side bolsters were a little more beefy or adjustable, though. The rear seats are quite cramped, and I wished Audi would have made the cavernous trunk a little smaller so that passengers would have a little more legroom. They'd almost be more comfortable laying down in the trunk. If you've ever seen the truck of the S4/A4 you'll know what I mean. ;) If the trunk wasn't big enough for you, you can also fold down the 60/40 rear seats and fit your groceries for the next 6 months in there ;)
Audi placed 2 cup holders under the center arm rest...hello? You need to keep the arm rest up if you want to use either of these cup holders, but luckily there is a neat little retractable cup holder in the center console that you have more direct access to.
Driving with the sunroof open at highway speeds creates a loud droning sound between 35-45 mph. This is very annoying, but my solution is to drive faster :) It's unexcusable, though, to have this happen on a $40k+ car (never had this problem in my Integra). There is also wind noise from the side mirrors at highway speeds (a slight whistling sound), too.
To use the cruise control you have to fiddle with a stalk on the steering column. To accelerate after you activated cruise control, you press the button on the end of the stalk, but to slow down you have to use a different slider switch (which also serves to turn the cruise on/off). Clumsy to say the least; I wish they placed the controls on the steering wheel like my old Integra.
Exterior
The Avus rims are a huge brake dust magnet. I've been told that applying car wax to the rims will help with cleaning. Any which way, I think I'll be cleaning off brake dust quite often. I didn't like the styling of the rims initially, but it has grown on me and now I like them.
Audio
The Bose system sounds pretty decent for a stock radio, albeit a little too heavy on the bass. I listen to a lot of bass-heavy music (trance, house, hip-hop, etc.) so the system's bass-heavy emphasis works nicely for me, but it gets a little irratating after prolonged listening sometimes. I haven't really cranked it up, but I have heard from others that the bass gets muddy at higher volumes as well.
Maintenance
Every 2001 Audi comes with a 4yr/50,000 mile warranty (2001 models received a longer warranty than previous years), during which time all scheduled maintenance is included with the car purchase...even down to replacing windshield wipers.
Summary
Wow. Go get one. You won't be disappointed.. You'll notice that the negatives that I wrote up are really all minor nit picks...consider this a plus since I really don't see any major downpoints with this car!