An easy way to make once car sporty is to add this superuse classic: An old tennis ball used as cover for the tow ball.
Tow Tennis Ball (since the tennisball)
All over the world where there are cars, tow balls and tennis.
Picture made by MediaMisfit of his own ball, http://www.flickr.com/photos/mediamisfit/2357607805/
, placed with kind permission.