Yes or No on a new 09 A5 Questions inside. TIA
 

I have a 06 A6 with 48K on the clock and the warranty runs out in June 09. I have had a few problems with the A6, heater core, front end work and the growling when turning from the rear end. I like the A5 and having the new warranty with the new car is appealing. The A5 is in the $50K range and they would give me $18500 for my car. Any questions I should ask? Thanks in advance.

Not sure what advice you want. If thats a good deal on your A6 go for it. Lease deals on A5 haven't been great.

It seems you put a fair number of miles on your cars, so yeah, if you like the idea of factory warranty, it might be time to trade.

I can't speak to the reliability of the A5, as we've only had ours a little over a month (not a single problem so far, I'm happy to report!).
My '05 A6 has actually been pretty good overall as far as reliability goes, outside of a few minor problems which we've had a hard time getting fixed (this may be a dealership issue as much as an Audi issue).

As far as the cars themselves go, if you don't need the room of the A6, I would definitely strongly consider an A5. I don't think the driving experience of the A6 is very exciting, quite honestly, and the rear suspension is relatively harsh over bumps also (I do have the optional 19" wheels which makes things a bit worse). So while I hoped that the A5 would be better, I've been pleasantly surprised that the A5 is a LOT better! Audi has really worked some magic in the platform, and the car is actually fun to drive, yet rides better than my A6.

If you plan on getting nav, and aren't in a hurry, I might consider waiting for '10 model with the 3G MMI.

Good luck.