Here's my opinion.
Being a Sumo wrestler is similar to being a H!P performer. You have a list of strict rules of conduct (written and unwritten) that you must follow by. A H!P performer is discouraged to have personal relationships due to losing many fans with money. The same goes to a Sumo wrestler going places in a car (which seems to be a luxury in Japan). I guess Geishas could also be included in this discussion.
Sumo wrestlers train to be the best of the best and driving a car to get around instead of walking/jogging seems lazy in some eyes.
I say, let the wife do the driving. Are there cars that comfortably fit a Sumo wrestler that can drive?
