Anyone know what this structure is ?

Does anyone know what this metal support structure is for? It's under the car just forward of the spare tire well. I've tried to upload an image but it's not working so I'll try to describe it. The metal support is a trapezoidal box extending downwards from the frame about 4 to 5 inches. The thing is about 1.5 inches on each side at the bottom. It's just forward of the spare tire well and has a metal plate that also contacts the spare tire well. It's dead center left to right, and just behind the rear wheel suspension cross bar.

I'm having problems with the Coastal hitch flexing so much with a bike rack on it that I'm looking for a way to give it a touch more support. We are looking for a place to weld an addition support to the hitch to reduce the twisting taking place in the hitch's crossbar. This structure is directly inline with the receiver box and a couple feet forward. Welding a bar from the hitch to this structure, probably putting an L bracket to the bottom of this so it distributes the load evenly on the flat surface at the bottom of this interesting structure, would pretty well take the flex out. That is, as long as this structure is strong enough to take that kind of upwards pressure, and the frame members it goes into are good for it as well.

What did Toyota put this in for? It clearly had some design purpose given the amount of additional metal it represents, and there are specifically placed holes in it.

Has anyone solved the Coastal Hitch flex problem in another way?

Thanks.

 

<div class='quotetop'>QUOTE(Tom_06 @ Sep 29 2006, 10:21 AM) [snapback]325620[/snapback]</div>

Way cool. If that can take the weight of the back end of the vehicle, it should certainly be able to take the much smaller forces generated by the bike rack whose weight is carried by the hitch. The only only forces applied to it are from the bounce of the rack, and they would be at the end of a 2' or more moment arm, so fairly light.

I'll check my owners manual in a few days. I lent it to a friend who flew out to Chicago to pick up his Prius today and will be driving it back this weekend.