[Jack21]

Horns? Anywhere you like where they won't get in the way of anything else. Just be sure to run a ground wire from the horn frame if you mount it to the body.

Footwell air? Not necessary. First off, ceramic coat your headers (or preferably the entire exhaust) so you're not generating as much heat in the engine compartment. All your plastic, and rubber parts will last longer. Second, use the carpet padding CR sent you for patterns only. Don't install it in the car. Use double faced aluminum padding (about $40 a roll from Summit, only need one roll) for the footwells and trans tunnel. Single faced aluminum padding for the rest of the carpeted area. Local Trak, Pep Boys sells it as Van and RV insulation, $20/roll along with the 3M spray adhesive you need to install padding, and carpet.

Result, no roasted tootsies from engine heat or exhaust. In fact, footwells don't even get warm unless you turn the heater on.