Re: decent speaker for a garbage ride...
Front: (use mdf or a cheap adapter to fit)
WoofersEtc.com - CL-S50A - CDT Audio Classic 5.25" 2 Way Component Speakers
edit: Forgot that 6.5's will work with an adapter, too... so these would be better if they can fit in the budget.
Rear: WoofersEtc.com - SE8375 - Eclipse 5 x 7" 3 Way Coaxial Speakers
Run the CDT's off the amp and the Eclipse's off the hu. Use the remainder of budget on a couple of sheets of Audiotechnix 60 mil deadener.
SoundQubed 6.5 Pro's DD T2 Tweeters / Phoenix Gold Xenon 100.4
FI SP4 15 D1 w/ Tantric Sounds softies / DC 5.0K
Singer 310 6 phase 2 runs of Monster Cable 1/0 / Exide g78 AGM under hood and XS D3100 in rear
Plenty of deadener. CCF and fiberglass insulation in doors... thanks to the advice of keep_hope_alive they sound AWESOME! :-)