Cost: $7.88 for wood, already had other supplies
Time: 30 minutes, plus time for glue to dry
Theory: This is basically a nice-looking board to mount the amplifier and crossovers on so they don't fly around in my frunk (front trunk).
Opinion: This was definitely a quick and easy way to clean up the frunk. I went for a simple design with no extras, just a simple wood base for mounting. I had to do a bit of extra work to round off part of the board so that it would fit well above the spare tire. I made the fit a bit snug so that I would not have to use any actual mounting pieces to hold the rack down (keeping the spare easily accessible).