[RoachRage]

Mine is gone after getting tired of messing with the screws. Hated it. It won't be coming back.

 

[RoachRage]

On the Flex, we were told that it was specific to the air flow in the engine bay. If we removed it, the turbulence would prevent the turbos from getting air flow (heat extraction) as well as noise in the cabin. I just presumed the same thing here...

I know this is the case in the 1970 VW bug I had. Being an air cooled engine, one does not effe with or remove the engine sheet metal. I just presumed the same thing with the Focus.

It's actually more complicated. The sheet metal shroud around the VW motor served two purposes, neither of which was to improve aerodynamics. The VW motor brought cooling air in through the vents under the window, and in later years (70+) through even more vents in the engine cover which it pushed through the fan shroud, cooling the engine, and which then exited under the car. The purpose of the shroud was to prevent the hot air from recirculating back into the engine space, causing overheating in hot weather. Air entering through those vent louvers under the window was also used to blow air through the heater ducts which was then forced across the heater boxes that are wrapped around the exhaust system and then into the cabin which served as a heating system in cold weather. So the second purpose was to prevent exhaust gases from being pulled back into that engine space which would cause those gases to enter through the heat into the cabin. Not a similar situation at all.