What's up guys, I just bought a 98 Audi A6 this weekend and I'm loving it, big improvement over my 99 Saab 9-5!

Now, even though I don't mine the system, I'd like to upgrade, add a couple 10'-12' in subs, new speakers, and amps. I'm pretty clueless on the whole car audio bit, Saabs are a bitch when messing with the audio system, so even basic details would be helpful.

I'm looking to spend about 1500 total, so help me out. What speakers, subs and amps are best/fit?

Thanks in advance!