Is there any way to get more air into the engine compartment besides a hood scoop and opening up the hood?
I did a couple of things that improved my engine temps when sitting still.
Got rid of the big plastic engine cover and replaced it with the DDMworks stainless cover.
Got rid of all the baffles and intake muffling parts and replaced them with a straight CAI pipe. (also DDMworks).
No improvement noted while driving, but that was never a problem to begin with. My temps when moving are always around 190F. biggest improvement was when sitting. It seems that opening up the top and right side of the engine by removing all that stuff has lowered my sitting temps by around 10F.
Two things to note: The CAI filter is for all practical purposes, in the same location as the OE filter. IMHO the air being ingested, since it is coming from the same location, is no cooler than it was before, it just allowed me to get rid of all that stuff beside the engine.
The original big plastic cover on top of the engine, according to GM, was to cut down on engine noise and to allow engine to warm up faster. that could be so, I guess, but I see no difference in warmup time without it and no difference in engine noise.
In summary, removing those two OE items has improved my engine temps at idle.