Food for BBQ?

We're going to a BBQ on Saturday evening. We don't *have* to bring food, but I'd like to and I'd like it to be something a little fancier than potato chips and Coke. However, the car will be fairly full of other things so we don't have room for a cooler (unless it's a tiny one) so anything requiring refrigeration is out (we have to drive more than 2 hours to get there or I wouldn't worry about it). Any ideas?