My favourite's still the Trabant 601 (600 wait, one gets it). [Linked Image]
Cute plastic body and fantastic 2-stroke sound. Only alternative is Citroen 2CV. The 2 cylinder engine doesn't sound bad either. And the body... it was the last car for centuries to have the headlights seperately on a piece of pipe and not incorporated in the hood. And don't forget the fantastic suspension! The French used to know how to build that.