I have heard a couple people state that it works well up until the first wash. Teflon will not bond to a surface unless the surface is first heated to 680*F. Unless you plan to heat your car to 680*F, this Teflon stuff is crap.
i used the dupont teflon stuff on my interior once. it was horrible! it left my dash spotty, i threw the bottle away. just use the good old stuff, there's a reason it's not "new".
its kinda like that oil with teflon in it, actually ended up killing oil filters much quicker than standard oil, and wasnt any better as far as protecting anything. basically just gummed stuff up. i wouldnt recommend it.