Car speakers?

I know this is a little out of the realm, but a friend is looking for 6x9 rear speakers and 6.5" component speakers (with separate tweeter) for the fronts. He's looking to spend about $150 for the rears and $300 for the fronts. I think he'd stretch a little if there were significant improvements to be had. Haven't looked at this stuff in 20 years so any thoughts/recommendations would be greatly appreciated. He may also need an amp so any thoughts there would be helpful as well.
I have a car audio system with Polk components up front and 6x9s in back powered by a Rockford amp. They are in the budget. The speakers and amp can be found at a lot of different car audio shops. I am happy with it. My former car had an Alpine amp with Cerwin Vega speakers which I liked too.
why not go to best buys site and click on car audio and enter the info requested and it will give you a list of what speakers will fit the car.

Could also try Crutchfield as well.
mbquart car audio speakers are very popular.
JBL P963 6x9 with outboard crossover 96dB, bought mine off ebay new @ $100/free shipping. They have 3 matching 6.5 versions with the outboard crossover.
If he's a audiophile he should look into cdt audio. they are the best bang for the Buck. other brands he should look into are Hertz, dynaudio, or focal
2nd the motion regarding dynaudio/focal
look at the focal 165 component fronts and matching rears, which are in your budget (there's a couple of models so make sure they fit the car)--sonix electronics seems to have the best prices.