The steering wheel buttons got all gooey on my grandfathers 03 CLK430 with 35k miles on it. No idea what caused it, however it lived in Florida with the top down, so I could see the UV thing but that car was always garaged at night or whenever at home.

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68 280SL - 70 280SL - 70 300SEL 3.5 - 72 350SL - 72 280SEL 4.5 - 72 220 - 72 220D - 73 450SL - 84 230GE - 87 200TD - 90 190E 2.0 - 03 G500

Nissan GTR - Nissan Skyline GTS25T - Toyota GTFour - Rover Mini - Toyota Land Cruiser HJ60 - Cadillac Eldorado - BMW E30 - BMW 135i