Hi Mike, thanks for the useful post.
It seems that I have a lot of water spots but on my front windshield. They are not circular like the one in your pictures, but more like water that has ran down the windshield after a rain lets say and stuck there. Like the water spots you have in your mirror in your bathroom when water fells over it and starts following downward course (gravity) and the dry out.
I have tried several thinks to clean them with no apparent results (and I fear a lot in case of doing any damage in the windshield). Things I have already tried are:
1) Prima Clarity Glass Cleaner
2) Optimum No Rinse as a cleaning water solution (1 oz/2 gallon of water)
4) Tar & Glue Remover (in case it was resin from pine tree that fell during the rain with the rain water)
6) cleaning washing the whole car with a neutral Ph, no alkali,no acids, no wax shampoo.
Despite the measures 1-6 above the water spots remain there. I applied all the above with waffle weave mf towels and I dry the car with waffle weave towels.
I don't know what else to try (my last options that I can think of are clay - with ONR in clay lube proportions and a glass polish cleaner).
But I fear a lot not to scratch or do any other damage to the windshield.
The water spots can be seen only under a specific angle and sun/light conditions and especially when the windshield's wipers are sweeping by drying the windshield.
What else can I try because I am stuck and the car is only 1,5 months old and I can not accept/cope with it.
Thanks in advance.