Both the mypod and little guy trailers would work for a gas smart car but the little guy would be at the upper end of the weight limit as per the European spec. Hard to find an exact weight for it. The website shows it as smart car compatible. It would be a nice combo but if it has a dry weight of more than about 600 pounds I would pass. It would be overweight for the diesel. The diesels forte is mileage (71 mpg) not towing. Ours do OK with our trailer but it is under 550 packed...with Kayak. Dry trailer weight is around 320 pounds. Even towing in 5th gear (the diesels are a 6 speed) we get 48 - 52 mpg according to our scan gauge.