There are many cars smaller then the Insight. Here is a list of small cars that I currently own. BMW 600, Citroen 2CV, DAF 600 (inventor of CVT), Subaru 360, Morris Minor, Geo Metro. Here is a list of small cars I have owned in the past. Messerschmitt KR 175 & KR 200, BMW Isetta, Vespa 400, Goggomobile 400, Bianchiana 500, Fiat 500, 600, Multipla, Honda 600, Mini, DKW 3=6, Skoda, Subaru Justy, Chevy Sprint.
All those small cars got good milage but none of them got as good milage as the Insight. I once got 76 in a Subaru 360 and 88 in a Isetta, but that doesn't top the Insight's 92. The three cylinder cars,( Sprint, Justy, DKW, Metro) will all do around 90 mph, not even close to the Insight's top end.
When comparing the Insight with these and other small cars, the Insight is far and above all other small cars in comfort, reliability, speed, and MPG. ON the other hand the Insight could learn a thing or two from the older small cars about weight control, space utilization, and size. There are several 4 seat cars that are smaller and lighter, even some made in Japan today. Problem is people don't want to go head to head with SUV's in little cars.
Louis