Ryan,
This post probably doesn't answer your question specifically, but tells about the car's behavior in stop-n-go situation.
Posted by Archie 02-14-2008, 07:00 AM in Forums>Smart Car Community>Smart Car FAQ's>Engine heating the car? entry #20
«Archie, Location: Katy, TX
Non-issue. The cars used for the road show were test driven/idled for 8 hours at a time (in temps up to 110+, in Phoenix/Chandler, AZ, for example). Day after day, city after city. The carpeting gets warm and that's it. A/C is more than up to the task.»
So, if those "demos" sustained our abuse day after day, apparently without problems, maybe some aspects of your worries are somewhat quenched?