Defective exterior windshield markings??

I was at a car/truck show over the weekend and visited with a brand new Ram SRT 10 owner. He showed me some visible straight lines on the "exterior" of the windshield. These lines only appeared when the windshield was wet (with Windex) and disappeared after the windshield was dried. No notice of these lines from inside the truck. Initially, the lines looked like they were made from the wipers sitting in the "on" position. Long, perfectly straight lines about 1/4" wide. The windshield has some type of "darkening" coating on the exterior and these lines (one on the driver side and one on the passenger side) were lighter in shade than the rest of the windshield. I ran my finger nail over these markings and could feel any "etching" or scratch lines.

Next time you clean your windshield look for any of these lines..again, they only appear when the windshield is wet and I could not see these lines from inside the cab.