I saw it on Pennocks last week. Hard braking causes oil to run out of the leaky valve cover gaskets onto the manifold. The oil could ignite into a small fire and cause the plastic channel that the spark plug wires run through to ignite and cause a major fire in the engine compartment. The solution is to remove the plastic channel that the spark plug wires run through.
My question is: If the leaky valve cover gaskets are the culprit, why remove the spark plug wire channels? Because it's cheaper, and if you later have a fire, they can blame it on something else, because they've already fixed the problem.