Newblet, As an audi owner. I have to say. Unless you plan on servicing your car yourself, you will be in for a treat.
1) Audi stopped giving free maintanence first the first 4 years.
2) Audi service is not going to be cheap, especially with the latest FSI engines. For example, the oil change isn't simply a oil filter. They went to a canister approach, which means taking it to your local jiffy lube (even if you dared) probably won't work.
3) Audi/VW's has a terrible depreciation record versus BMW and Mers.
4) The A4's current styling is due to expire in 1 year. You'll definitely get hit with depreciation.
A5/S5 is coming soon, followed by the next gen A4. While the next gen A4 looks more and more like a passat, the next gen will have better weight distribution, and the S4 is rumored to return with a bi-turbo v-6 instead of an V-8.
If your are definitely an audi-holic, I'd at least wait for the 2008/09 a5 or a4. One thing you'll notice is all current generation audis have a pretty hefty front overhang and as such are pretty nose heavy. This is all fixable with suspension mods, good set of tires, etc. But why bother. Also next gen quattro systems are rear-wheel biased, unlike current gen. (You are going to get quattro, aren't you?). Also, the DSG transmission is not available on most cars except the A3 and TT (haldex quattro). Tiptronics and CVT transmissions blow, and the manual will be slightly soft unless you get a S4/S4/S6/RS4 (so I'm told).
5) I have not found a trusted mechanic to service Audis here.
6) While my audi's reliability has been decent, it's definitely NOT the same as a honda.
7) You will enjoy the driving dynamics. But for you, will it outweigh everything else? For me it does, because I like to tinker. For you it might not be.
8) Leasing an audi is a bad idea. Buying a used one is also worse. Most people don't do proper maintanence. It's especially a bad idea to buy a used audi with the 1.8T or 2.0T or the 2.7T(found in the B5 generation S4) engine without really knowing the history behind them. For more information, go to audiworld and search for "turbo" and "oil coaking(sp?)". Basically, it's what happens when people run a turbocharged car hard such that the turbo is glowing red and shutoff the engine right away over a long period of time (over 4-5 years). Audi's don't come with an after-run oil pump, so oil doesn't circulate after you shut the engine off, which is bad if the turbo is glowing red.
That's why I run full synthetic, have a turbo timer that lets the engine run 1-2 minutes after I shutdown, and do oil changes after 5000miles even with synthetic.
You're young. If I recall, you were asking for 401k advice. At the same time, you're going to take out a loan/lease a $30k car? Shouldn't you be saving for a house? 🙂