I rather like the design of these cars (Nissan Cube, Scion xB, Honda Element). The design is functional in the amount of interior space present in the interior of these vehicles.
One truly streamlined automobile that quickly became a joke was the 1949-50 Nast Airflyte 600 and Ambassador models. These Nash models had a much lower coefficient of drag than the cars from the other U.S. manufacturers. They were comfortable cars for 6 passengers and the streamlining had a purpose.
One non-streamlined vehicle that came out right after WW II was the Jeep station wagon. It was probably the Nissan Cube/Honda Element of its day. Yet these Jeep wagons were very functional.
I think that the ugliest cars made were the 1959 GM products–particularly the Cadillac with its high fins. These GM products weren’t even very functional. I remember my Dad road tested a 1959 Buick–he was going to trade in his 1954 Buick. The seats were hard in the middle making this a 4 passenger car. I remember my Dad teling the salesman that “I’m not going to pay $3300 for a 4 passenger car”. We were happy to drive away in our 1954 Buick.
IMHO, if there isn’t a function to the design,the vehicle is ugly. I think some of the recent Chrysler products are ugly for that reason.