I don't like it one bit, and I refuse to supply my VIN.
1) It's a way of tranferring liability to the customer: That's the VIN you supplied, it can't POSSIBLY be the wrong part!
2) It's a hassle. Why should I wait in line, go the desk, find out I need a VIN, go back to my car, find a pen, find paper, write the VIN, Is that a zero or an O?, come back, wait in line, wait for the monkey to punch in 16 characters, and then... "We don't have that part in stock, would you like to order it?" Prepay of course.
3) It creates a data base uniquely identifying: You, your car, the part. Whether or not we are being "tracked" is only a question of semantics. No, Subaru isn't doing this because they want to get in our business. BUT, IT IS A SEARCHABLE DATABASE!
The implications aren't hard to imagine. Say vehicle X is used in a homicide. It's unregistered, but the local dealerships cough up their records. Someone transposes a "1" for an "I" and suddenly you're being investigated for murder!
Here's another one. Let's say we decide that global warming is a real threat and all cars must have all stock functioning catalytic converters. Let's say that modifying a vehicles emissions system becomes a $1000 misdemeanor with up to 90 days in jail (equivolent to driving w/o tags).
Would it be hard to imagine the local cops going through the dealership records to find who recently purchased up-pipe gaskets?
Here's what I do if a dealership asks for VIN:
* First, "Just say no." Cause a delay, ask to see the manager.
* If that doesn't work, go to a different dealer. Make it clear, that they're losing business over a damned computer program.
* Don't have another local dealer? Buy online.
* Finally, offer to supply the first 8 (or so) digits of the VIN. This is a comprimise. They can still get all the information they need, but it does not uniquely identify the person and the car.