Bluesman, silicone is hard to get off the windscreen, smeary in the wet, and if you use it on paintwork, then some waxes won't stick properly.
It is other people's bloody silicone, too.

If you watch the NZ film 'The Fastest Indian,' that looney used boot-polish on his tyres. I change them, I'm funny that way. I've HAD a tyre blow at speed.

My old Dad was a long-time motorist, and he had lots of wheezes and get-you-home-fixes. Fuller's Earth for a slipping clutch, chewing-gum sticks to a holed petrol-tank, Mint Humbug sticks to oily steel.

Then there were the ones to disguise worn mechanisms when you were selling the vehicle...