There has been a lot of car-makes-art stuff lately (BMW paintings, Aston Martin ads, etc). But I think this is the most thoughtful example because thankfully, the letterforms are not solely influenced by the car's abilities. Instead, the driver and the car are challenged to execute letterforms that have been well-designed beforehand. The final product is a nice balance of aesthetic vs. process.
UPDATE June 23rd, 2010: The Belgian agency Happiness just won the Design Grand Prix at the 57th Annual Advertising Fesitval in Cannes for this "IQ Font" campaign.