What is this part and do I actually need it?

[Elkins45]

I think you are looking at the wrong item. I was too a first until I read the the first picture was off the internet and NOT the OP's car.
A thin plastic cover wouldn't rip the mounting bolt out of the floor pan like this did.

I’m the OP. It wasn’t the cover that ripped it out. It was the chunk of wood that I ran over. The cover just came along for the ride.

It was still hanging on by the rear bolt when I pulled over but I couldn’t pull it the rest of the loose by hand. 40 miles later when I got home it was gone.

 

[JohnnyG]

^ If that's how you want to look at it.
So, all the other parts are in place?
Also, you have the part in your hand and can't figure out what it is or send a picture of it?

 

[Astro14]

I believe you answered your own question. "The front edge of the fuel tank......" I would put it back on.

I would, too.

Look, Toyota added a couple bucks to the cost of the car to add that pan.

Was it for drag and 0.01 mpg?

Was it to keep crap thrown up by the wheels from getting packed around the gas tank?

Was it to keep debris from hitting the front of the tank?

No idea, but they spent the money to put it there, so I would replace it, because it had a purpose.

 

[Elkins45]

If the purpose were to protect the front of the fuel tank it seems odd that it extended down toward the ground rather than backwards to actually cover the gap in front of the tank. If you look at where the rear bolt is you can see it ends before the tank space begins. I’m wondering if I could use a flat plastic sheet and accomplish the same thing?

Regardless, I’ve found a pick and pull in Cincinnati that has a couple of xBs on the lot. I’ll snag one and a couple of other parts I need this weekend.

So, all the other parts are in place?
Also, you have the part in your hand and can't figure out what it is or send a picture of it?

I don’t have it in hand. It was still there when I stopped immediately after the impact but by the time I got home the wind had torn it off. If the scrapyard has one I’ll post a photo of it before and after the install. Like @Astro14 said it has to have some purpose or they wouldn’t have paid to put it there, but it sure doesn’t seem like it’s much more than an aero deflector or splash guard.

 

[JohnnyG]

delete

 

[Elkins45]

I spent $10 at the pick-a-part today and pulled one off a wreck. Here’s the part by itself and installed. I really think it doesn’t do much except maybe deflect a bit of water or road debris.

 

[meep]

Looks like an aero deflector found on a bunch of Toyotas. Used to direct air and debris away from the rear suspension components from what I understand

Similar part from a Prius with a more useful description: https://www.toyotapartsdirect.ca/p/...n-Splash-Shield-Rear/49386041/5762747010.html

"Cover. Floor. Shield used to direct water / debris away from the Floor pan. Pan Splash Shield. Side Member. Protector. Underbody Shield."

^^^ this is the most plausible to my guess.. there’s one on each side. There’s no electrical or plumbing underneath it. It’s not structural.

If so, bravo that Japanese cars are starting to take underside aero more seriously. German makes have been doing it for decades.

 

[supton]

I like to think of parts falling off my cars as weak parts leaving the body, leaving the strong behind.

My guess, that's for MPG and perhaps noise, cut down on wind noise maybe.