I just picked up and installed the Kenwood 10" Sub/Amp/Box combination, and let me tell you it is a great fit for the tC. It takes up roughly a quarter of the hatchspace with the seats reclined as far back as possible.

It does 100w RMS and 200w peak, and beleive it or not is more than enough bass for the car. I wanted something to pick up where the Pioneer system left off, providing nice highs and mids, but severely lacking in bass output.

For $250 for the unit, it was a great buy that gets the job done. The wired remote with gain control and center fQ adjust is very nice, and allows a bit of fine tuning to match to different music.

The ported box does allow the sub to be outdriven during intricate bass lines, but it still performs well.

Pics when I get the digi cam to work.