I recently purchased some subs and an amp real cheap from a friend, and am deciding where to mount the amp. The top of the sub box is too narrow and mounting on the back of the box would push it too far out from the back of my trunk. I'm thinking about mounting the amp upside down under the rear deck.

I was warned however, that in this position the heat sink would not be as effective and the amp could overheat easily.

Questions: Since the air inside the amp isn't moving, the heat would not rise because there would be no colder, more dense air, so wouldn't the heat sink be just as effective on the bottom as on the top? It's an alpine V12 amp, any chance it has an auto shutoff if it gets too hot?