Smoke?

I don't want to discuss the latest doings of a certain bint who was a winner of the Lucky Sperm Lottery, but this part of the story had me wondering:

The 29-year-old Hilton was in a car driven by a friend that was stopped when officers noticed what they suspected to be marijuana smoke coming from it...

Does marijuana smoke look that different from tobacco smoke that it would be distinguishable as it emanated from a (presumably) moving car?

I'm thinking that this one isn't going to survive a motion to dismiss for lack of probable cause.