Back in 2002, I had one of my friend lend me his Isetta 300 for two days, during the F1 weekend. Not to tell you, but that little thing was such a chick magnet. It even drew more attention than the latest Ferrari. Some folks thought it was BMW's answer to Mercedes' SMART car. Did I have fun in traffic with its one cylinder engine that would not keep idle. I had to double clutch at every gear change and use the gear shift on my left hand side. That thing, as small as it is, sells for around $25k in mint shape.
A nice and cheap alternative to the Isetta 300 is the Isetta 600. It has a twin cylinder motor and is roomier. It is the equivalent of similar product offered by FIAT in the same period.