Just replaced the battery in my 2010 RX350, which is well-situated beneath the array of plastic air baffles held in place by those push-pin fasteners. Not only are the fasteners a bit of an annoyance when you are more interested in what's underneath the baffles than the general appearance of the engine bay.

My main concern is that these baffles, while intended to provide a better under-hood view, in fact trap an excessive amount of super-heated air (important to those of us in a desert setting) and we all know that heat is a definite enemy of wiring, vacuum and fluid hoses as well as the battery itself.

What are the thoughts on simply removing these air shrouds (my 07 RX350 has way fewer such panels and runs ever bit as nice even with her 181000 mi).....

 

On my 07 is350 I took them off for that reason. The only issue I see happening is more noise from the engine compartment as these plastic pieces tend to dampen some of the engine noise.

 

May have in mind that many manufacturers heat test their cars in Death Valley and South Africa as well as cold test them in equally extreme environments. I'd leave them as intended by the Toyota engineers.