[Christ]

What about adding something like DynaMat to the areas of exposed sheet metal between the open areas of the structural webbing?

While DynaMat is normally used as a sound deadening device, it also has large basis in use as a heat-reflective material... lining the bottom of the car with it will help to keep cabin temps down.

That said, it's obviously covered with foil, which is heat-reflective, and might help to keep the heat from being absorbed by the hood and released into the atmosphere.

Cobra - When you say that heat retention is not necessary, you fail to logically understand the concern of the OP.

His concern was the if you warm the engine, it's more efficient than a cold one. Thus, keeping the underhood area warm will obviously keep the engine warmer, and it will run more efficiently from the first minute of the next start. He's not talking about retaining heat for hours, or days, but minutes. maybe an hour.

by the way, if you have read anything on this forum about efficiency, you would know already that heat retention is key in making an engine more efficient.. this "the OEM didn't do it, so it won't work" mentality is BS. It shows a considerable lack of evaluation skills. If that was the mentality of the rest of the world, we would not have most of the things that we have.

Please think twice before poisoning the board with this type of information.