I've often wondered about the use of letters. We are pretty innured to it since we constantly are looking at the backside of automobiles with a cacaphony of the alphabet (Super Roadster XXX). But I've been thinking about the choice of letters. "A" is a good letter. Its the first letter in the alphabet and connotes "the first" as in "A number one." We never say "B number two," but, there you are.
Going through the alphabet one runs across "G" as in "grand." I guess it is often combined with other letters as in XG or LG. Of course L brings up the idea of "luxury," definitely a carry over from the car world. "M" would be medium and "R" rare. And, I think as a second letter, somehow "R" comes in. I don't think its a first letter. "S" conveys "speed" or "super." I would think of it as a second letter except for the "SST." This always sounded so much like "PSST."
The most interesting letters are at the end. "X" is over used. We have Excel, etc. I guess that this is where its use comes from but I would also suggest that it is a holdover from the 50's where the experimental fighters and planes were always X-something. Interestingly enough, X is also the female chromosome and that makes for a strange combination as in X-men. You don't every hear of Y-women, do you? In fact, "y" is hardly ever used. You don't see a car named an "LY." I wonder why. "Z" is a good letter to use, but, again, in combination. I don't know what it connotes except "the last."
Sometimes its fun to think of something other than Karl Rove and Rush Limbaugh and, horrors, "W."