Just my 2 penneth, I don't think smoking whilst driving is dangerous at all, as Horney said it takes no concentration, the only thing I wouldn't recommend is rolling a tab/bifta on your knee while driving, thats just unsafe. I'm much more concerned about Polish lorry drivers pulling 50ton round roundabouts while on the phone!!!
As for smoking in a car, I personally do, but I hate a car that stinks of it. As a result I NEVER smoke in my car while sat in traffic, ALWAYS have the window open as much as possible, and always keep it near the window. I refuse to use the ashtray in the car, its always IMO been placed in such a daft place in a car where if you were to flick it there its inevitable your gearstick gaitor will get covered in ash, and also an ashtray even half full STINKS! (I usually have an empty can/bottle in the "bin" (under armrest) to put dockers in) But it mainly doesn't bother me because I'm so damn anal about how clean my cars are inside and even if I ever drop some ash anywhere I hoover it up asap
