Take Maserati for example. The exotic Italian brand offers potential buyers who take a new Quattroporte for a spin a pair of Bose headphones valued at around $179. Lexus doesn't even bother with a gift -- its dealers straight up offer you a $100 American Express gift card for taking the new IS 350 for a spin. Bentley is a little more subtle in its giving by offering to donate money to the Breast Cancer Alliance if you try their car.
Of course, such deals aren't exactly available for the average Joe, and the old trick of turning up to the dealer wearing a suit probably won't work either. You'll have to be on a mailing list targeted towards "high net worth" individuals or receive a private invite from the dealership.[Source: New York Times - Sub. Req'd via Automobiles Deluxe]