What I was told is that the glass that was labeled aftermarket, in US plants, was glass that failed QC for OE standards. Definitely still better than the really cheap stuff from foreign plants.
How?, the monogram (logo) would be different. They can't be removed and rebranded. First off that would only apply to aftermarket glass made by the same manufacturer of that same OE glass. Even in that case, once the auto manufacturer insisted on having their own branded monogram, that possibility went away years ago. Due to the monogram, once it is manufactured it can't be downgraded from OE to aftermarket.
FYI, I worked in one Pilkington manufacturing plant and visited most all of them in the US at least once in my 18 year old career. That includes a float plant, multiple temped glass plants , value added plants and windshield plants. It is a fascinating process going from from sand to finished part.
If there is a Chinese owned factory in the US making glass to OE standards that’s great, I’d get OE glass from them, but I'd avoid their non-oe for a new vehicle.
See that would be my preference for aftermarket glass, same exact part made using OEM tooling with identical processes on the same manufacturing lines as OE, with the only difference being the logo. All they would do is swap out the silk screen and keep running.
How would you buy OE glass direct from the supplier anyway? You would have to go through a dealer selling service parts and I've never bought a genuine OE part that stated who the supplier was. You wouldn't know until you received it and looked at the logo.
Of course, since I've never claimed a piece of glass on my insurance as the cost is close to my deductible anyway, I tend to shy away from paying a lot extra to have the manufacture's logo on the same identical part.
But there is another category where super cheap glass is shipped in from abroad. I’ve seen it with my own eyes the waviness and lensing was obvious under certain angles. We had customers complain and had to get OE glass to fix it. The more glass you put in, the higher chance of scratching the A-Pillar and causing damage, it's annoying to have it done multiple times.
I wouldn't buy a lot of cheap auto parts made overseas with a name I never heard of either. yet insurance companies are the ones that dictate their use in many cases. Anyone getting a windshield replaced from a glass installer usually doesn't have a choice of brands; they have what their distributor sells.
Customers who’d complain about AM glass, before the ADAS days, we’d make them feel better if we knew it was Pilkington and gave them the “this is who makes OEM glass” spiel. It worked most of the time.
If it was a General Motors product that would be a true statement. When I worked for them they had over 50% of GM business in NA and had been supplying them for over 75 years. In the 30's through the late 60's they had 99% of it.
Aftermarket glass can’t use the OE logo and there is a question of warranty issues or if ADAS failed in the future and you go to the dealer they can say you need a windshield, sorry, OEM requirement. I’d rather get it done right the 1st time on a modern car. For my 20 year old Toyota? I’ll take some AM glass, probably can’t get OE by now anyway.
If I had an issue with ADAS systems that caused a crash due to a substandard part put in my car by an insurance company, warranty would be the least of my concerns compared to a product liability lawsuit.