Our laser cut, 16 gauge aluminum Under Engine cover for the AE86 chassis is intended to replace the factory plastic unit that came with some models. There's no center cutout for the sump in this design - we wanted to introduce some aerodynamics to the under body.
Two columns of 3" louvers were incorporated to help in evacuating hot engine bay air - this is accomplished by the lower pressure the car generates beneath itself while in motion.
The stainless steel button head screws were chosen not just for long life but also to maintain an aerodynamic surface as much as possible. The stainless neoprene washers are to minimize any surface scoring and distortions as well as act as natural spring tension to help keep the mounting hardware secure.
AE86 under engine cover
x2 stainless M6x1.0x20 button head screws
x2 stainless M6x1.0x30 button head screws
x4 stainless neoprene washers