Why does your car dealer need your thumbprint? Its for your protection, silly! Unless you don't want to be "protected." Then you're not getting a car. From Lornamatic, the blog of a carless but still clean-thumbed customer:

You are handed a slip of paper and told to mark your right thumbprint in a box. The paper says clearly that it's a request, for your protection, and to prevent your identity theft.

When you politely decline, the dealership refuses to sell you the car.

This is precisely what happened to me today when I tried to purchase a new X3 at the South Bay BMW dealer in Torrance, California.

Let me restate: In order to buy a car, with cash, you must authorize the release of your official DMV-recorded thumbprint to the dealership. This is not a law, this is a "dealership policy."

Brave New Car Dealer: fingerprints required to buy a car? [lornamatic via BoingBoing] (Thanks, Jason!)