1) Park car
2) Check temperature, ensure that it is below freezing
3) Plug in block heater
4) Sleep
5) Come back in the morning, unplug block heater
6) Wipe off frost from windows
7) Start car

If you feel like you've awakened a vengeful wrath of a shaky, oil-burning German beast when you turn the key, it's likely your block heater isn't working.

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2003 Volkswagen Jetta Wolfsburg Edition, "Tiffany," - Black/Black Cloth - 75K miles, Jetta #6; my faithful, turbocharged, BBS-adorned sled

SOLD 3/08 1981 Mercedes Benz 300D, "Elise" - Astral Silver/Black M.B. Tex - 217K miles - I miss her everyday; the best-built car I've owned