ninsei

Just did some work under the car for the first time and was confused by the 3 large torx bolts holding the rear of the plastic undertray on. Unlike the other smaller screws, these 3 are attached to a structural brace. Do they serve any other purpose than to hold the plastic under tray on? If so it seems like overkill.

markN1689

idk but they are required to be removed to take off the bumper

ninsei

I assume the small ones in the front are required to remove the front bumper. but I'm talking about the three big ones towards the rear of the front under tray. They're torqued really tight too.

mroberte

If removed, you could potentially get some rattling/slapping from wind turbulence under the car. To me, looked like they used them to not have to use a washer, they are pretty shallow bolts.

Fixeroh

I purchased the aluminum skid plate from ECS Tuning not long ago. The plate actually mounts to those bolt holes. Uses the existing holes from the plastic cover as well of course. Very solid, very nice mod. Really necessary? Probably not but it definitely protects the underside of my engine bay. ALL of it. Sure there is an aero factor as well. One thing that sort of shocked me was exposure of the composite oil pan on our cars. There are some electrical connections on the bottom as well. Small plastic cover does NOT cover them at all. I live in Ohio and I could see chucks of snow or ice getting up there. Knock on wood but our winter has been super mild this year so far anyway.