The world's smallest road-legal car, the Peel P50, is currently on display at Ripley's Believe it or Not! Museum. Only around 50 were made in the mid-1960s, selling for just under £200 advertised as being able to hold one man and a shopping bag.
With only one door, one headlight and no reverse gear, the P50 certainly won't attract the ladies (they couldn't fit in anyway) but it'll certainly squeeze into the tightest of parking spaces.