All of the research I've come across indicates that the Astro Ventilation markings on the passenger and drivers side windows was discontinued part way through 1968. However, I recently looked at a 69 RS SS Convertible I'm considering buying that has the "Astro Ventilation" markings on the driver and passenger side windows. The car has 86000 original miles on it and has been parked by the current owner since 1983. She bought the car in 1972. I grew up in the same town and remember the car well. Everything about the car appears to be completely original and I have no doubt the current owner is telling me the truth when she says she has never had the windows replaced which might have explained why "Astro Ventilation" appears on the windows. The car, built in September of 1968 was sold through a dealer in Canada. Any help in figuring out this mystery would be appreciated. Even the codes don't make sense to me. It's possible, the original owner might have had the windows replaced for some reason but that seems unlikely. The original owner bought the car new in the same town where the current owner lives. It's a smalll town and no one I've spoken to remembers anything ever happening to that car before the current owner bought it. If anyone could help with these codes I'd certainly appreciate it. The drivers side window is a Soft-Ray Solid Tempered Window with: AS 2 , UX and M55 stamped on it. The passenger side is also a Soft-Ray with AS 2, NX and M74 stamped on it. Any assistance in figuring out this mystery would be greatly appreciated. I have photos of the windows if that would help.