Originally Posted by
StSebastian
Technically the "Y" modifier in the front is supposed to mean "premium" within that class. Thus "F" is full-size, and "YF" is premium full-size.
I have to admit quite frequently I can't tell the difference. The only thing I know is that I'm not allowed to pick up Tauruses unless I'm by myself (while I may not care, someone else does).
There is a pretty clear difference with the Y, and your premium sums up the designation.
Y_ means:
you cannot reserve that specific class. it is only available on day of upsales and upgrades.
premium--usually some of the following: leather seats, sunroof, special trim packages, a car slightly more luxurious than the rest in the class, but would not fit into the next class.