is under the passenger seat a good spot to mont an amp or will it overheat?

 

it depends, is the amp going to be running hard and hot (i.e. 2 ohms played loud for long periods of time), or is it just an extra amp maybe to drive the high speakers. if it wont be played very hard and it will fit under there then go for it, but if its gonna get used alot i would mount it in the back. If you realy want you could put it on stand offs under the seat and mount a computer cooling fan thats how i have my amps under the seat in my jeep.