In cars, what does the acronym GL, GLX or SLE after the model name stand for?

The abbreviation GL stands for Grande Luxe (that is, more added bits than a 'de luxe' has.) Presumably GLX is fancier or faster. SLE sounds like a Mercedes Benz thing. They have their own system. I think that one is a sports car. I think the one I used to drive a chap in (to meet his girlfriend - she drove the rest of the way) was a 300SLE.

SL is super luxe, and SLE is probably super luxe extra. Mercedes also have various initials that are in German, like SLK, where the K stands for 'kompakt'.
Only CL there has foxed me, but I know most of the other obscure ones as well, especially those used by Honda if needed.

These are trim levels. Here are some examples I googled up and took out of context:

trim selections: GL, GLS, and GLX

three trim levels: SE, SE Sport and SLE

Available in 5 trims, ranging from the SE to the SLE Convertible.

Their origins go back to the once universal terms Grand Touring, Deluxe, Grande Luxe and Sports/Special, since abbreviated to GT, DL, GL, GLX, GLS, SS and so on. They will vary from one manufacturer to another.

https://itstillruns.com/difference-between-gls-glx-8449188.html