Music! I'm upgrading my sound system now. It already has the Kenwood DNX9980HD, Helix B Five amp, Infinity speakers in the front and sounds awesome. When I finally get the kickers in the door and the other Infinity speakers in the rear I'll be estatic.
There's nothing quite like a spirited ride through the twisties (or just straight line speed) while listening to some great tunes with the top down.