Mecum's upcoming Indianapolis auction will include the sale of one of the two surviving GT40 Roadster prototypes.

And you can buy the conversion kit for yourself – but if you're in the U.S., you might have trouble finding the host car.

Bluetooth car kits let you talk hand-free while driving. Consumer Reports checked out GoGroove FlexSmart X2, Belkin CarAudio Connect AUX, Jabra Journey and Motorola Roadster 2.