I didn't know you were actually planning to use these *in* your car. For some reason, I thought you wanted them that big so you could fit them in your trunk to transport, lol. :P Oh well, brain fart.

Honestly man, from someone who is extensively into car audio and also has owned and used a lot of the kappas, I wouldn't use them for a car audio application. I suppose if you already have them and just want a temporary setup, it's not a bad deal at all, but I wouldn't buy them specificaly for my car.

Sound quality would be greatly improved by using a single unit in a 5 cuft enclosure. It won't be as loud as the pair, but it will sound better at least... So I guess it depends on what you want more.

Adam