Perhaps a better method of biometrics is to use voice recognition systems. This article discusses it in the context of activating a credit card, which seems like a dorky reason for implementing the technology to me. If the voice recognition system could "serialize" your voice down to a series of numbers and then transmit that with your credit card transaction -- that would seem like a decent way to verify credit card transactions.

It also seems it would work better for auto security systems, as your fingers don't necessarily need to be attached to you to activate fingerprint systems.