If you keep the sub in its enclosure and securely mount it in your trunk, you should be fine.
Nope. You'd need an inverter.i have a 10 disc changer in the trunk so there's at least something hot back there that i could potentially use to power it?
If you're willing to dig into the power requirements of the amp and see if it can accept DC power, you MAY be able to get a regulator to power it.
But an inverter is the easy way to accomplish what you want.