
Car sales lady: "This window tint reduces heat by sixty percent. So when it's forty degrees outside, it's only fifteen inside!"
My first thought was "Damn good thing we're not working in Kelvin, then!" My second was "...somebody really needs to use this stuff to build a perpetual-motion Stirling engine." Afterwards I was pleased to hear that Rey had had exactly the same reaction. I married the right woman :-)
CSL: "This protective coating is made with something called polytetrafluoroethylene."
Me: "Oh, Teflon?"
CSL: "...something like that, yes."
The painful bit was when she told us she'd studied chemistry herself so she understood this stuff. Not to mention the repetition of "the boss won't like me doing this, but I'll offer you a special rate...", which really wasn't very convincing the first time, let alone the third.
(We had already agreed to buy a car from one of the other sales guys, but we did not end up getting the tint, coating, sound deadener, antirust treatment, or any of the others.)