I got an Aiwa head unit/Cd Player from my brother in law and Im not surehow to get the old Audi/Blaupunkt Cassette player out without damaging it. Is there some sort of Wiring Diagram I should see before I try to do this DIY ? Or should I just let BestBuy install it ?

 

If I were you I would stay away from Best Buy when it comes to installation.
You are better off going to a shop that specializes in Auto stereos, like Ed & Al Sound. They do this for a living and you will find the same guys year after year working there, unlike the Best Buys of the World where they just put some poor untrained kid who will quit after he used up all his discount provileges at the store...
You may pay more, but your dasboard and wiring won't get butchered. Just my $.02...

 

I'll agree with Zippy here. A buddy of mine went to Best Buy, and nothing worked right after they installed his stereo. In fact, the installation was so botched that it ended up frying his speakers. As far as removing the factory stereo, if it's a DIN unit, you can get tools to pull it out yourself, and if it's newer, probably a wiring harness as well, at your local Wal Mart for cheap (at the Wal Mart in my town, the DIN head unit removal tool is about $3, and wiring harnesses run about $5). And, if you have any experience with electronics, it's generally not too difficult to hook up a stereo yourself. I'm not sure where you're located, but my advice to you, if you don't want to try to do it yourself, is to find any of the numerous shops that will do audio installation. If there are a bunch of ricer cars cruising around town, see if there's a shop that they went to. Generally, if there is one shop that alot of drivers have gone to, it's going to be credible enough to trust. And they generally have enough experience to do the job quickly and cleanly. Otherwise, Google something along the lines of "Aftermarket stereo install for (insert car here)". I can even find stuff for my 1989 200 Quattro sedan, which isn't exactly the most common Audi out there. that's my advice