I just installed Megan sway bars and they look very cool painted blue. I want to show off the rear one by removing the plastic cover that is right behind it and under the trunk floor so the sway bar can be seen from under behind the car.

What is under the cover and is it functional??

 

Though the fins on the cover is not too pronounced, it was designed kind of like a diffuser to help keep the car stable at higher speeds. Is it truly functional though for this reason; maybe not. But Lexus might have designed it to help with the areo of car instead of stability. I doubt you'll tell a difference if it's removed though.

 

The cover allows a better airflow underneath the car. It all has to do with coefficient of drag. COE. COE affects MPG.

 

Yes I noticed the small diffuser air channels. I'm gonna take the plastic cover off to see what it looks like. If it looks bad without it I will just put it back on!

 

Looks good! I might remove mine just because it collects small rocks so I might clean those out for OCD purposes

 

If you take it off can you post a pic I want to see whats under the cover.

 

its an OEM diffuser and an under carriage for protection of objects flying up.

I have mine removed because I installed a custom diffuser. When I removed it, there were many small pebbles and debris inside.

 

Can you post a pic of your custom diffuser

 

 

i would remove mine once a year to empty out all the debris that collects in it. gotta save weight lol. nah it would just irritate me that if i tapped it while cleaning i could hear all the rocks inside it

 

Exactly, it drives me nuts!

 

Here's the diffuser I want to buy from ebay $75 plastic universal fit. I have to take off the OEM plastic cover and see how I can fit the new one

 

I took the cover off and underneath looks like the fuel evap unit and fuel pump--so I put the cover back on as it serves as protection from road debris. Im going to get the above cover, take the fins off and attach them to the factory cover!

 

i think youre better off going going to Home Depot and buying a sheet of aluminum or metal that fits and rivet or drill it as a diffuser. Those ebay things are plastic, poorly made, and over priced