How about a crazy early Bugatti as inspiration for a cardboard car to go along with cardboard houses. The lines are almost completely devoid of compound curves. Change the colors to red and white and it would be perfect. I have no association with the ebay seller, just wanted to share an interesting style with other readers.

http://www.ebay.com/itm/O-M-OM-KIts-Ref ... 5d5b0efda3

Love this!