Just because a girl smiles at a guy at a stop light dosen't mean shes a whore with multiple STD's. Sounds like a few people are trying to bring you down. I say go for the girl and see whats up. You never know, she might be a keeper. In my own opinion, 3 out of 5 girls are dirty whores anyway. But, she might be a good girl. (How many girls were in the car?haha)
Let us know!!!! Oh yeah, chew some Big Red before you talk to her. She'll smell it. And thats a good thing.