Then of course you can ask what others see you as in chat also.
Best thing is to just use names when trying to get someones attention.
Things get really confusing when people start spouting out numbers only.
Now let's say you make a copy of your car, name the file "f99_118.car"
(which will replace one of the fantasy cars that came with the game), and
sign on with that car when you go into multiplayer. Everyone will have that
file in their "CARS" folder and everyone will see you as the 118 car.
They'll all see you as the green Mike Maiers Rab-O-Tec car, but at least
when the chat shows "HEY 118, STAY OUT OF MY FENDERS!!!" you'll know they're
talking to you.
If your car # is any of the ones that came on the CD (like 18), you could
also replace the "c99_18" car with a copy of yours and most everyone will
see you as the Labonte car, #18.