Ford head unit does not pre-amp out puts and if i were you I would replace the head unit before the speakers. You will hear a diffrence in sound with a better head unit, the shelling out to up grade better speakers.
Now as far as getting your car smahed open I would reccomend a Elcipse head unit. They call have come with a manfucature warrenty saying if its get stolen out of your car within a yr. then they replace it free(with police report) the thing with this head unit is that when the head unit loses power only the CD you had programed works. Now enless u tell someon or write it down somewhere in the car its the best thing next to your pin number.
Chow
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ASP UnderPully,
SCA Cold-Air-Intake w/MonsterFlow airfilter,
Bullet Exhuast w/High-Flow Cat 2.5 Piping all the way,
Koni Adjustable Struts,
Eibach Springs,
SCA 21mm rear Sway Bar,
17" TSW Imoma,
Brigestone Potenza S-O2 225/35/17,
Push Button Started,
Carbon Fiber Dash,Door Sill,and Sail Panel,
PIAA Lights
Eclipse 5504 Head Unit,
Diamond S600s Hex Front Speakers,
Diamond M55i Rear Speaker,
(4)JL Audio 10W3 Subs,
Rockford Fosgate PA2 Preamplifer,
Rockford Fosgate Power Punch 800@4 Amplifer,
(2) Rockford Fosgate Power Punch 800@2 Amplifer