I smoke cigars in mine ... never have the window as far as half down inasmuch as that far down and some of the ashes will blow back in ... also, I keep the fan on at at a low-medium rate which creates a positive air pressure inside the car and "pushes" the smoke out the window ...

In addiition, I have a 'ozonater' that plugs into the lighter socket ... this device is not a gimmick, it WORKS ... there is no odor of any kind lingering in my car ... it smells fresh and clean all the time ...

the ozonater is a device that I bought from a company in PA ... it cost me $115 ... I was turned onto it by a friend who had been using one in his new truck for about a year .. he smokes a cigar in his truck every day and after a year of doing so, his truck still smelled like new ... that sold me and I've been extremely happy with the results ...

I'll send you info on where I got mine if you have any interest ...