Next thing you know their car goes up in flames like it's front bumper was made from C4, you run to help them, but they're crossing four lanes of traffic on foot faster than Frogger.
So you walk back to your vehicle and see the accident left you with some dents, and a flat tire. You pull apart the back of your car to see nothing but a tire iron, and a can of this stuff.
This is when it dawns on you the dealer stiffed you on the spare tire. So you pump this goop into your wounded tire and if it doesn't ooze out from the inside, it's gonna give ya a mile or two to make it to a garage. Good luck finding a replacement can of the goop anywhere easily accessible, but you will find it here!!