I've got the Driftbox, which is a $250 upgrade from the $500 Vbox. It just adds information about drift angle, which is interesting, but questionably worth the extra money.

Great system, easy to use. Just take the memory card out of the unit and pop into your computer. They have some track maps to download, so they may have your track already. Unit suctions to your windshield, and you are ready to go. Great support too.