Pull down husks and remove all the silks. Pull up the husks and soak in large bowls of cold water for 30 minuites.
Preheat Grill. Blot dry corn. Pull down husks and brush corn with butter. Place husks back over corn and twist ends to close and keep in place. Arrange corn flat on grill with ends away from direct heat and cook, turning often until tender(about 20 minutes).
Remove corn and pull down husks. Spread mayonnaise on each ear, then sprinkle with chili powder, red pepper, and parmesan. Serve with lime wedges and salt and pepper.