i have the 6.5" kickpanels and like the looks of em, but i recommend a 5.25" speaker. the problem is thta speakers like enclosures behind them and its hard for a 6.5 to sound any good in the kickpanel of a mustang. there is not much air volume behind the speaker. get some good crisp 5.25 2ways or 3ways if you want a lot of treble. id go 5.25 infinitys or alpines. then put either 6x9s or 6.5s in the back but install the back ones so there is a lot of space behind the speaker. i put my head unit in the glove box so no one would see it, leaving the stock one in place. you will want to get something that is hard to steal since it will be visible in the middle of the dash. eclipse has a good anti thrft device in thier stereos, but the units run 300 (very good unit and has power). go either two tens or one 12 woofer. keep it simple with JL W0s or alpine type S's, then throw in a 300watt rms 600 peaks amp. should sound good.