Car companies occasionally offer incentives to test drive their cars. Typically they send something in the mail that you would bring to the dealer to fill out after the test drive. However, for most of the offers all that is really needed is the dealer's id code (BAC). This is a way to get the dealer ids for GM (without having to go down to the actual test drive - the dealers actually rather you not waste their time by test driving a car that you have no intent to buy).
Go to that link - make sure to add the zipcode - and just search in the page (ctrl+f) for "dealerId". That's the dealer code. (There will be ~25 dealers listed in the page - use whichever you want.)
