I cant stand the "plastic bag" cover over the entire hitch. It drive me nuts for some reason seeing that. As far as the tennis ball goes it just has a 1" hole cut (I used a utility knife) in it to clear the ball shank when its on there in place and I cut 1/2" slits at the 12, 3, 6, and 9'oclock position to allow it to slide over the ball. Ive also used the rubber glove trick pre-tennis ball.
*Currently trailer-less but shopping
07' GMC Envoy w/ P2 controller (current TV)
88' Chevy K5 Blazer (soon-to-be TV)
74' VW Superbeetle (1303)