Rolling down the windows doesn't always work. Me and my friend smoked a bowl with the windows down (while driving) and we came back to my house with my mom home sleeping. She comes in like 20 minutes later and says that we're "Fucking stupid if we didn't think she could smell it when she walked in." She was pissed.

But, anyway...I would say, cologne, even perfume if you have a girl (sounds weird but you can always just use the excuse I went to go see her and now I smell like her, that's what I've done) anyway, then...like they've said Febreeze or even Air Freshner or Oust.

Oust is good, too.

If you smoke, ciggs are also another route.