I believe they bin vehicles by available seating and not by things like luggage.
There is no option to say “send me a mini van”
So it can carry the 2 extra people, it can carry some luggage, it can't carry both, and it can't carry neither?
While NAND is technically correct, it's just not commonly used as a grammatical conjunction.
I thought it was just used for, like, a couple jokes that you get from “intro to digital logic” class. The joke is funnier if it is correct, I think.