Glass rules have me confused


Apologies if this is a newbie question but I’m trying to figure out the rules for glass in the 4 doors. I understand from that I can remove the rear sliding glass, but that I cannot remove the fixed triangle of glass. But the newer rule implies that plastic rear windows are fine, at least for the 2 doors, and that the 4 doors can install “fixed windows”, which I think means fixed plastic windows. I’d like to go all plastic windows in the doors, both sliding and the triangle. Is that ok? 2 door cars: Rear passenger windows may be replaced with a clear polycarbonate material no less than 1/8” thick approximating the size and shape of the original. A NACA duct may be mounted on the window. Additionally, pop out windows me be replaced with a fixed mounted window and vice versa. Fasteners which allow for easy removal may be
used. 4 door cars may install fixed windows. This rule does not apply to the Convertible as per




I have the same question.


Brett, you can’t replace the little glass rear passenger window of a sedan with something non-OEM., as you said, makes it clear that you can’t remove the fixed glass in the rear sedan doors.’s phrase “4 door cars may install fixed windows” is giving us an alternative to windows that are “not fixed”, as in “go up/down”. That sentence tells us nothing about the little glass rear passenger sedan window that is addressed in The sentence tells sedan owners that their rear passenger Lexan window can be, if they like, fastened in place instead of having to go up/down.


Thanks much for the clarification.

I’m guessing the rationale for the Lexan in the 2 door is to make it easier to get into the back and the 4 door doesn’t have the same limitation. Any chance of allowing all Lexan in the doors regardless of model? Sure would make the rule simple, would be cheaper if broken, would let me use that junkyard door with no glass…


Yes, it was about helping coupe owners access the rear of their car. I finally, after the rule being in place for 16months now, just put Lexan windows in the rear of my coupe. It’s really damned nice to be able to get to the back. I can undo the 4 big screws in 1min, easy.

Everyone’s welcome to submit a rule change request. In my early days I used to pepper my regional guy with these all year long. Got lots of them approved too. Here’s the process. Requesting Rule Changes