Thanks for all the suggestion. And I will use a different car wash and maybe try some of that spray one wax.

But, just to make my point. It is raining in the bay right now. My merkur which sits in the sun and rain all the time still beads up even though I have not waxed it for at least 6 months. But the ML does does not bead up and I can feel contamination on the side as I have described earlier, seem to me that I have no wax there. Of course I don't drive the Merkur in the snow.

Does the snow and mud really do that much to wax?

This weekend I think I will use some cleaner wax on the side of the ML to get some of the contamination off. Let see how the cleaner wax hold up after the next ski trip.

__________________
Silver Honda Accord, 2006
Silver G500, 2003
Silver SLK-320, 2002
Black ML-320, 2000
Bule Porsche 993 Targa , 1997
Silver Merkur XR4Ti, 1987