Actually, from the front, they do have a little difference. I hope I am not the only who sees this - but i think the GLT looks a little smug-gy as compared to the GLE. The front-grille looks a little more snout-ish as compared to the GLE, which is a bit longer.
Internally, from my observations, and I didn't have a lot of chances to observe GLTs as my friends prefer the GLEs and SEs due to the ages (GLT the youngest would be 1994, whereas GLE youngest is 1997-same year as some S70s), but what was clear is the electric seats that were available on GLTs. GLEs does not have this luxury (or potential danger, whichever way ou look at it).
I own a
1994 GLE Wagon (permanently borrowed by wife)
1993 GLT Sedan (bought to replace above stolen car)
GLE doen't have
Electric seat, cruise control, leather or half leather seats, no sunroof, no front headlight wipers (although optional), wheel options, rear parcel shelf cover, fog lights, auto AC