I think the cloud cars fit nicely in with the overall design of Cloud City. They would not work at all as outer space fighter ships. More like early-to-mid 20th century automobiles/police cars/ambulances combined with the Mustang posted above. In between an art deco car and a fighter jet. Cloud City seems like a peaceful place with mostly civilians but obviously those Cloud cars are flown by some kind of officials [edit: Bespin Wing Guards].

The PT went a bit too far with these types of old-timey civilian-ish designs, though.