I'm doing some market research. I'm considering building and selling a device for the aftermarket that would allow you to access your vehicle using your fingerprint. This would be a lot like those keypads that they install on Ford vehicles. To access your car, you could use a key, a remote, or a fingerprint.
Installation would be fairly challenging, and would involve cutting a hole (or possibly just drilling one) into the door panel, as well as some basic wiring inside the door.

In answer to the first question that will surely be asked: Yes some guy in Malaysia got his finger cut off, but he was using the fingerprint as part of an ignition cut-off, while this will simply be an additional method to enter your car. If you don't want to lose a finger, hand your keys to the thief and walk away.

What I want to know is this: Are people interested in this? How much are they willing to pay?

Note - I hope this doesn't violate the ban on commercial posts, I'm just trying to do some basic market research before jumping in.