Windshield marks from wipers - how to remove

Try using some tooth paste to buff the marks out.

 

In the hope that it's just really gooey wax, try some non-polar solvents: alcohol, Goo-Gone, paint thinner (keep that off everything except the glass!).

 

It's probably just road grime. I have used SOS pads (the kind with detergent in them) for cleaning my windshield. On the commute from Portland to Seattle I have had to use them as many as 3 times to remove the buildup. I carry a package in my Prius and they really work without any scratching problems. Aso all washer fluids are not equal. I tried RainX and went back to 20/10.

 

If there is any dirt buildup on the wiper blades, especially sand, that will easily scratch the glass

Drag your fingernail across the mark. If it feels like your finger is catching or dragging like in a groove, the windshield is badly scratched.

If it feels more like a residue, that can be removed with either a paint scraper or patient buffing. Experienced window techs can use polishing compounds to take those marks off glass, no need to replace a windshield

The worst windshield marking I have ever seen was from a friend who had his car repainted. They used sandblasting media to clean off the paint near the pillars, and the windshield cover had slipped. The edge of his windshield became opaque

He hunted down a good window shop and they were able to polish out most of the opacity. Of course, a slight haze was always there

I looked around and Eastwood Co has such a kit

Eastwood Co. - Glass Polishing Kit Pro

 

I asked about water spots (somewhat related) and grime on windows to my friend a professional window washer. He said use white vinegar mixed with water, what ratios I do not know at this time.

ZC1

 

Tooth Paste is not as abrasive as you might think it is.
There are some commercial window polishes on the market..
I'd avoid the harsh chemicals some have mentioned, you don't want to take a change that some of it will drip on to your plastic trim or the car finish!
Boni Ami or a glass stove top cleaner may also work. Try some Baking Soda.

 

You can also go to an auto parts store or automotive paint store and get a "wax removal product" this is what some of the paint shops use to prep the surface of a car before painting. Its a liquid like car wash concentrate you mix into a bucket of water.

 

You want to avoid abrasives that are strong enough to polish the glass, as an inexperienced user can introduce optical defects that will ruin the windshield, but you need something strong enough to remove the film.

Some people I know clay the glass on their car. I've never done that, but I have used the Diamondite system with "spray clay" (not the polishing cream, which the inexperienced user should avoid). Pricey, but it will do the job.

Diamondite Spray Clay, Diamondite Glass and Surface Cleaner, Diamondite Shield, Diamondite Speed Clay

Zaino Z-12 and DP Glass Restorer would probably work too:

Z-12 Clear-View Glass Polish: Zaino Store

DP High Performance Glass Restorer actually removes etched water spots from glass and restores perfect clarity. DP High Performance Glass Restorer can also be used to remove sap, bug splatter, and films from chrome and windows.

 

After all this time and many experiments I have found a great fix for this-
Soft Scrub with bleach.
A quick rubdown of the windshield with rather light pressure with a rag wet with soft scrub removed all traces of rubber residue on the glass. Rinsed off and it looked like the day I took it off the dealers lot.

 

Product description includes the expression "mild abrasive", which makes me leery.

I like this stuff, not sure if's just Canadian though:

Kleen-Flo | Products - Glass Kleen

Reading the ingredient list is a little depressing though: use sparingly and with good ventilation. This ingredient is a known carcinogen:

2-Butoxyethanol