They may have cracks in them? My 17 had 3 lens cracked, replaced all 3, you can find the lens on ebay got mine for 5.00 ea. Dealer price is around 8.00
Also while the were off I waxed really good underneath them and put a heavy coating of wax on the screws.
Also while the were off I waxed really good underneath them and put a heavy coating of wax on the screws.