I did some searching on the forum for this, but no clear answers. Have 2007 Sport model, probably normal interior for that, CD radio w/mp3. Looking to replace speakers with something better... are the speakers likely 6 1/2"? Another user inquired about the watt/channel output of this standard Radio/CD, but got no replies. Anyone know the likely output per channel of the stock radios? And I should add for additional info.... are the stock speakers 4 ohm? Thanks.