Okay, so.. anyone who knows anything about car audio (and isn't some 22-year old college drop-out with a rice burner) will tell you that the best value for your money is Blaupunkt all the way around. It outperforms a lot of equipment that almost doubles it in price. They also have a line of subs that are thin enough that they can fit inside your car door (depending on the model).
[quote:2fd55]Want a Subwoofer in your door? No problem. Thin line speakers once again prove that thin is always in! Thanks to our exclusive "Fringe Field" technology, the TH speakers give you high-end performance and power handling in a remarkably lightweight and low-depth speaker.[/quote:2fd55]
http://www.blaupunktusa.com/BlaupunktUSA/Products/
The link above takes you right to their list of products. <3 German engineering.
EDIT:: I forgot to mention. I used to have a Pioneer head unit in my car. I don't recall the model number, but I paid somewhere around $300 for it. Awhile back I bought a Blaupunkt head unit w/MP3 capability for $105 and it kicks the shit out of my Pioneer in performance.
Also, a buddy of mine had a system in his Jeep that consisted of an Alpine head unit, 2 10" Rockford/Fosgate subs and Pioneer 6x9s. After he replaced his head unit with a Blaupunkt, he was so impressed that he has spent the last year replacing everything with Blaupunkt. He went with everything from the Thin Series and it sounds 100% better than his old system. Also, he was able to get a really cool enclosure made that houses both his sub and his amps and gave him back almost all of his trunk space.
Damn, I should work for Blaupunkt or something.