'38 Buick Y-Job. Can't buy one; it'd have to be built.
Chevrolet Astro show Corvair. That would have to be built too.
Porsche Speedster replica- yes, I'd rather have that than the real thing. Hop it up with a modern drivetrain, perhaps diesel.
American Austin/American Bantam. Just because they are sooo cute! I suppose I should try to get in one first though...
As long as I'm dreaming, I'll take a Pillbug please.
Early Lancia Stratos. Probably doesn't really belong in my Top 5 list but I've always liked the styling.