what's that smell?

Driving the other day I keep smelling something in the distance, not like the smell of summer rain on hot asphalt, not the smell of popcorn or crackers near the Lance factory. No this was different, slightly intoxicating actually. By that I mean overwhelming, I tried but could not quite identify the smell. Again I smell this overwhelming fragrance, "where for art thou?" Just then I realized it was from the vehicle in front of me. Driving an average of 45 mph, I could smell this from approximately 2 car lengths. Every time we got to a traffic light it was totally enveloping, so much fragrance that my nose seemed to have been burned.
My question is, how much air freshener does it take to pass your gas to other vehicles on the road while driving 45 mph? I mean what would it have been like to have sat in that vehicle?
You talk about vehicle emissions, this was a black ball of green house gas.

I am not sure what he's trying to cover up, I do have a suggestion.... "close your windows, you're killing the rest of us!"

It was a little like walking by that person who is wearing polyester that has not been dry cleaned, well worn and freshened only by some perfume or cologne! A conflict for the nose, just as you catch a whiff, you gasp for relief.