MAN: First, you have to figure out the layout of your car's engine, or as engineers put it, your engine configuration, to find out where the hotspots are. In the 1950s, cars had large relatively uncluttered engines that were ideal for cooking. Simply put, in the 1950s, cars ran hot. Today, car manufacturers design engines that are more efficient, make less heat, and look like spaceships.

Manufacturers are increasingly replacing metal parts, the ones that are great for conducting heat from the engine, with plastic. And with the advent of the hybrid electric car, a gas engine is now paired with an electric one, making it a challenge to figure out which is which.