Hi! Newbie here. Glad I found you. I want to install an AM/FM/MP3 stereo that fits properly in the dash with a minimum amount of work. Any opinions on the Retrosound USA vs the USA-630? Or any other models out there that aren't junk? I'm also looking at some flat speaker boxes that fit under the front seats. Any opinions on those? I don't want to do any kick panel or rear deck mods, so these seem like the only options.