After a quite some hours, a fair few quid and a few different attempts at getting rid of the previous owner's smoking habit, I dropped an Airvidox chlorine bomb in the car for the best part of 8 hours on Sunday...the results are good so far. I've already used a mix of Autoglym high foam shampoo, Auto Finesse Total interior cleaner, an Autoglym air con sanitiser, new pollen filter, Dr Leather wipes, and the smell kept on returning, especially on hot days, and especially from the steering wheel and passenger soft trim/pleather between the window and handle when the sun hits it...it's grim...I even unbolted the front seats and vacuumed quite a lot of debris from the hard-to-reach places...The irony is that the interior is pretty much immaculate, apart from the smell, and one small burn/melt on the USB port, which I'll replace at some point. So far, the interior smells fresh and the chlorine smell is gradually going (which I'm happy for it to stay as it doesn't smell of fags!), The steering wheel still has a faint whiff of smoke, but nowhere as bad as it was, so I may leave it a few weeks and do the treatment again. I spent the time pre-cleaning with Airvidox' own interior cleaner (a solution you mix into a bucket of water), and even after I thought I'd cleaned the interior to 'as new' previously, the water had gone from golden to a grim brown once I'd finished, so it obviously picked up even more grime the other cleaners hadn't. So far it's done a lot more than the other cleaners I've used, and cost a lot less...I don't think it's completely eradicated the problem yet, so if required, I'll give it another go a in a few weeks...for around £20, it's certainly been a lot cheaper than the other options I've tried, which in all fairness only clean what you can reach and touch, whereas the gas gets in everywhere, the same as cigarette smoke. Hope that helps any other owners of cars which have been smoked in! Cheers, Nick