i removed my back seats to tuck away all the wires, there is room enough to fit the capacitor int here, but i was wondeirng inf the cap needed ventilaiton and shouldnt be put down there?

That could be a fire hazard, as the cap can heat up. I would not put it inside there.

so then it doe sneed ventilation to stay cool?

Yes, it needs to be as exposed as possible. It can be sunk in a little bit, in order to hold it in place, but mainly it needs to be exposed. Unless you want to hook a little fan up to it.

um, capacitors dont create heat as far as i know

"The Rockford Fosgate Reinforcement Capacitor should be mounted as close
to the amplifier as possible, within 18" (0.5m) of the amplifier, keeping the wire
runs short to reduce voltage losses in the cables. Use the mounting brackets
supplied to secure the capacitor as close to the amplifier as possible.
The capacitor may be mounted in any position; however, care should be taken
to ensure the venting hole on the top is unobstructed at all times. This vent is
a relief valve should the electrical polarity become crossed. Should the capacitor
be damaged, fluid will exit from this vent rendering the capacitor useless."

that was from a owners manual for a capacitor.

they say just a nice dry place, 18inchs from the amp.