This is funny because I was thinking about this just tonight. How about a powered home sub and just plug it into a power inverter. Then run the RCA's to the HU. I don't know how good that would work, but i'll just throw that out there for you to ponder.
yes they will work, like rovin said it really depends on whether or not your amp will support a 8ohm load if thats what the subs impedence is. A sub in an enclosure is going to put out the same output with 100 watts in a house or in a car but with different effects due to cabin gain and cars natural frequency tuning. Ascendant Audio Atlas and Avalanche were orig built for home audio but thay became big in the car audio business when they started using them for such. If you have a 10in home audio sub that has a rms rating of 150 watts lets say in its orig enclosure rated at 4ohms there is no reason you can't put that sub in your car.