It looks like my trip across America by SMART car was a resounding success. With only one minor, easily corrected hiccup along the way, my SMART car performed well. It was able to do the posted speed limits - which were as high as 75 MPH. Headroom was incredible, with a good six inches of clearance above my head, and the seat was comfortable. The heating and air conditioning systems worked well and, considering the diminutive external dimensions of the car, it had an amazing amount of space inside. Normally one person doesn't take three suitcases (I brought computer equipment, camera gear and two weeks worth of clothes, in addition to leaving some space intentionally empty so that I could bring back materials from the auto show), so your luggage would probably fit without taking up so much room.
My calculated fuel economy varied somewhat during the trip, from a high of 52 MPG after a leg between California and Arizona, to a low of 34 MPG after a particularly nasty stretch of road in California that included a long climb uphill in windy conditions. My average mileage was probably in the low to mid-40 MPG range. Then there is the rock star factor. There was hardly a time when I wasn't approached by curious onlookers when I stopped. They really liked the car and were eager to learn more about it.
See blog here.