I know this is grave digging but if you watch the openers from, like 2006, you'll see he's showing a nice bulge as he sits on the front of the cab. The second one, he tries to cover it up, but it still shows under his shirt hem and then the third one he's got his hand between his legs when they do a full shot.
The season after that the completely abandon the full shots for tight (upclose) shots.