I'm not so sure that you're gonna have ANY success totally removing the smell of cigarettes from a cloth interior. I have two suggestions for you.
First, an old trick used to remove odors from refrigerators is to get some BBQ briquettes...obviously not the ones that are self lighting, just the plain ones...and two shoe boxes or similar. Fill each box with briquettes, and put one of them in the interior for 24 hours...then take it out and put the other one in for 24 hours...and keep rotating them. While one is absorbing odor, the other is airing out and getting rid of the odors that the briquettes absorbed. Works like a charm in frigs, might work well for you.
And my other suggestion is to start smoking cigars in the vehicle. It works great to get rid of cigarette odor, guaranteed...