Can someone explain what these mean and what there levels are?
I know that:

SE: Sport Edition (or Special Edition?)
LE: Limited Edition
R/T: Racing Transmission
GLE: General Limited Edition?

What are GXE and ES?

 

The abbreviations don't really mean anything in particular. In Maximas, the base is GXE, then SE, SE AE, then GLE in order of increasing standard equipment. When you go to other manufacturers, the letters change. For example, in the Toyota Camry, the order is DX, CE, LE, XLE. The Mitsubishi Galant has DE, ES, LS, GTZ. The Honda Accord has the DX, LX, SE and EX. Like I stated before, the letters really don't mean too much, they're a marketing scheme (except for BMW, where the letters actually kinda mean something).

 

R/T is actually mistaken for A LOT of different meaning but the true meaning for R/T is Road & Track.

 

Oh, thanks. I always thought there was some universal system of ranking.