I didn't attach an amp to the ceiling of the inside of the car. Years ago (1993-1994) I had an 88' Honda Accord Coupe. In the area between the speakers in the rear deck I mounted an amplifier upside-down. I believe it had a built in fan. The car looked very factory, you had to crouch down and look up to see the amp if the trunk was open. In those days I didn't even consider a car PC. I was using an external Pioneer 6 Disc CD changer. It was mounted behind a spot under the radio that was dedicated for storing cassettes. I could remove the plastic cassette holder and even change CD magazines while driving. It was an RF modulated model, but I found the audio out from the CD changer's RF box, and wired it to a little toggle switch on the front of my cassette radio. I also cut the traces on the volume control in the radio so that I could select from two sources. Put the switch up, and it was normal, play cassettes and AM/FM. Put the switch down, and it was the CD changer. Wow, was I cool back then! LOL!