W210 1996 E320 Smoke Silver. [W124 1990 300CE Artic White - Sold].
I am not sure about waxing the windshield. Some carwash stations even give out towels with dewaxing stuff to remove the wax intended for the paint only and not for glas.Ok, here is the recipe!
1. Clean windshield with 100% household ammonia and dry.
2. Sprinkle water with hand on wind shield and wipe with NEWSPAPER until water is dry and glass is streak free and crystal clear. Don't worry it will not scratch glass.
3. Apply regular liquid or carnuba car wax on windshield and work it in using circular motion and let dry to haze.
4. Now wipe off the wax. Make sure you get it all off. First use terry cloth and then a newspaper.
5. Now do the inside.
In the rain, you will not even have to use your wipers! Water will not stick.