I saw where you had mentioned this to someone a couple of years ago or so. Are you saying there is a leak/crack between where the clear front mates to the housing? If so, I am assuming that the most logical fix would be a thin coat of clear RTV all the way around the housing.

I guess, at any rate, I should try the TSB fix first and see what happens. Your DTRL theory sounds plausible. I always use my headlamps while driving. Of course, they are not on while washing.