I know you don't want to hear this, but they are garbage. I bought a cheapie several years ago and the resolution on the screen was horrible, the audio processors absolutely sucked, basically it was a big pretty thing in the dash. Mine never actually made it into premanent install after I hooked it up to check it out....

At least get like a Clarion 500 or something. But if you want GPS, NAV, bluetooth, etc. you are going to have to pay to play, ie: alpine, pioneer, etc at around $1,000 each.