Here's a cleaning tip for the yellow nicotine stains left behind on surfaces- it works for walls in homes, and I would expect that it would also work for vehicle interiors (to a certain extent): LA Awesome, sold at the dollar store effectively removes the build-up. I use it in my carpet cleaner, and it helps remove stains and general grunge. You must dilute it, and don't use it on glass- ammonia and soapy water will work for glass- but it's an excellent cleaner.