If you do not mind doing the install yourself, $1500 will get you an AWESOME system. Over the summer I re-did my entire car-audio setup from stock.
Headunit, Component Front speakers, Mids in the Rear doors, 4 channel amp, 10" subwoofer, monoblock sub amp, custom box, and knukonceptz wiring.
I bought mid-high-end bands too like Eclipse, Rainbow, CDT, Image Dynamics. This is nice stuff, and I did it all myself for ~$1000-$1100.
http://www.bcae1.com/ will teach you everything about car-audio an average person should know.
http://www.glasswolf.net/papers/index.html as will this mans write ups.
Just check out http://www.woofersetc.com/, http://www.sonicelectronix.com/, and http://www.crutchfield.com/ for some good deals. And join a car-audio focused forum to ask more specific questions. I cant really suggest brands to you cuz idk if your going for a boom car, spl comps, or sound quality.
Good Luck!