I have two 10" Woofers from an old 'half-completed' home stereo project I started when I was sixteen. I haven't used them in years, they are still in great nick, as are the piezo tweeters. They are just sitting around doing nothing. I want to use them in a loudbox to chuck in the rear of my wagon.

This is project groovebox.

I want to house them in a dual sub-bin. The drivers are rated at 8 ohms, 160w each.

Can I use a car amp?
Do car amps exist that operate at 8 ohms?
If not, would I need to bridge the amp to achieve 8 ohm output?
Is that absolutely necessary?
Can I bridge the two drivers, into 4 ohms?
Would I need an extra car battery?