The Smart Fortwo should have been a revolutionary smart car. However, as explained by Yeah! Motor, “The obvious problems are obvious: the rear-mounted engine and fore-mounted cooling system means that a lot of heat passes under the passenger cabin.

On a warm day, this can effectively cook the folks riding inside—not a recipe for comfort. Despite its ultra low emissions and gigantic fuel efficiency—this is the first car on the list to offer a hybrid variant—the problems with the first round of Fortwos were legion and nearly killed the Smart brand altogether.”