Bone a haunch. Yearling is best (that's a 1 1/2 year old doe, not a 6 month old fawn). Work it over with a Jaccard. Roll it into a roast of uniform thickness and tie it up with cotton string. With a barding needle, lace the roast liberally with pork fat cap (off the loin--from your local slaughterhouse). Allow the bardoons to stick out the ends by an inch or so on either side. Pat the roast dry with paper towels, brush on a coat of olive oil and dust on your favorite rub. Put it on the rotisserie kettle and keep the temp around 350. YOu might have trouble keeping the temp this low unless you seal off the insert. Remove when the fat is rendered and it will still be red inside. Pretty damned good.
I've only done this twice. Good the first time, so I did it with the other leg. Vowed to try it with a vinegar based mop late into the cook, but may never get around to it. Too many other good ways to fix venison.
Takes less than two hours, if I remember. I suppose you could cook it slower in the WSM, and cook it into submission, but selecting the proper animal and preparing the meat correctly goes a long way toward having it be good med/rare off the rotis.