Anybody tackle this before? I've seen it a couple times and just left it be , because I didn't want to use a bleach/mildewcide without knowing the immediate or long term effects. A late model Tahoe I detailed today had it bad, and it brought to light that I need to find a remedy that won't damage the rubber any worse than it is. All I did was clean it and apply some 303, and it made it a bit better looking. Is the mildew permanent at this point? Thanks all . Dan the Guitarman.