Getting car swag (noun - item of promotional value) seems rather hard for such a huge industry. I know from working during a time period in the video game industry that promotional items are over saturated in that sector.
I myself in terms of car swag have received Team Corvette T-Shirts, a Chevy Indy Manufacturers Championship T-Shirt, and SRT bookbags all from the Baltimore Grand Prix. Also, all of these automotive branded bags from the MotorTrend Auto Show I attend yearly.
What car swag have you received?