Yeah that stuff lol. It's hilarious. Nitrous oxide is what they are playing on, but I don't think it would be good for the tires.
Actually, race cars often use pure Nitrogen in the tires. For that application, I would want consistent pressure too, but for Nascar, even that's dubious since it always ends up as a big demo derby.
A friend of mine in PHX has a radio call-in show for car repair and maintenance. One day, his brother called to tell me that the show was on and that I should call with a question. I did and after I told him my name, I said that I had heard of people using Nitrogen and other gases to inflate tires. I went on to tell him that I had some leftover tanks of MAPP gas & Propane and that I was wondering of it would be OK is use either to inflate my tires.
Knowing that he fully expects some nimrod to try anything that sounds like it might work, he went on with a serious explanation that it wouldn't be a good idea and at the end, he said "I think I know that guy". His brother called back, laughing his butt off.