I'm a bit of a car freak, so I've got several. But, I'd have to go with the late-30's Delahaye show car (basically a concept car before they were called "concept" cars). There were a few made for auto shows from the mid 30's to early 40's. Due to the fact that they have a closed front wheel well, however, it would only be possible to drive in a straight line. Thing of beauty, though. Ridiculously art deco -- looks like something that the wolf would drive in one of the old Tex Avery cartoons. 1937, 1938, 1939 below:
On the other side of the spectrum, the 1957 Fiat Jolly is pretty damn cute, too.
Same question.