Amps under seats

[kiato4]

Hey all:
I was wondering if anyone had any experience placing a 4 channel amp under a power seat in a 190e (passenger side as drivers side has the cruise control and alarm boxes and there is no room there). Will the amp get enough air flow to keep it cool? What about under the rear seat, will it flow enough there? Finally, I am looking at new head units, and was wondering if 2v preouts for the front and rear speaker channels is sufficient or if there is a noticeable difference if I step up to 4v. Where would I hear the difference? Thanks very much in advance.