You can add a fuse and wire them up like that....
See the suggestions here about that:
LED's are fairly easy to mount and wire up, the LED strips you find on amazon or superbrightleds.com would do the trick. Some come with self adheisive strips on them, then its just a matter of placing them where you want and running wire from the fuse to the foot wells. If you understand basic wiring, you can easily add a switch somewhere if you want to be able to turn them on or off that way.