Bought one 6 months ago 2008/08 Quattro S-Tronic. Pearlecent Red, Panoramic Roof. Got wheels powder coated black and the windows tinted black. Also bought a Super Chips Bluefin for about £350 which takes car from 200 bhp - about 240 without affecting the MPG. Cars fitted with allsorts of goodies as it was an ex demonstrator.
Bought the car at 49K and at 56K he Timing Chain tensioner went and completely knackered the engine, luckily Audi supplyed and fitted an exchage engine for free as a gesture of goodwill because the car had a full Audi S/H. I'll be putting my car into the Audi Dealer to be serviced for sure, well worth the extra few £££ if your getting looked after as well as that.
I've got no regrets buying the car, in fact i'm well chuffed that I did, the only thing i'd change it for would be an S3 or RS3 which aint going to happen because of the cost. as for petrol vs diesel I suppose that depends on what you value the most power or economy, glad I got the petrol. Was thinking of getting a diesel but this one came along first and i'd imagine it's much more fun to drive than the diesel version. I can't see past the 4 wheel drive, which is what drew me to getting an Aidi in the first place. I had a loan of my m8's VW Golf 4 Motion and loved it. The only ones that I could find were the R32's and they were just too thirrsty on the juice and no where near as cool as my A3 lol. I got winter tires fitted and drive from Aberdeen to Glasgow every 2 weeks. Got caught in a full on blizzard one night half the cars on the road had to pull over as you couldn't even make out the road at some points and my Quattro kept going at about 60-70mph over taking range rovers provided I could see where I was going.
If your after a car around the size of an A3 and the price is right i'd go for one of these things, as I said unless you can afford an S3 or somthing and also like I said, what you value most fun & speed etc or economy. I'd also recomend the Quattro version if you can get one, but I do stay in Aberdeen so I really get the good of it in the winter.