With license plate info - a perp can find your address easily. If your car isn't locked in your garage, it could be stollen and gone in a few mnutes. Either jumped and driven off or simply towed away. With the way Speedsters are built (chopped VW pan), it would be simple matter to apply a new VIN and resell "your" car.
Years ago VS had 3 (?) Speedsters stolen from their build facility - none were ever seen again.