Sunpass is like EZ pass everywhere else, it is a prepaid toll that allows you to drive through without stopping; but in this case being used to describe a whore who "lets everyone drive right through." this term is similar to a door knob where everyone gets a turn.
"hey i got with this chick last night"
"really who was she"
"don't know here is a picture of here"
"o her dude she is a sunpass"