What is this part called and where can I buy one?

A 2002 Jeep Liberty didn't pass vehicle inspection because of this part rusting near the rear axle control arm. I've been looking for replacement but can't find it anywhere. I don't even know what it's called.
Can you help me?

Here's a picture from the other side for reference:

That's part of the unibody, I highly doubt you'll find a replacement for that one piece. You might check with metal fabrication place and see what they think. If that doesn't pan ask a farmer those guys are always welding stuff back together.

duderz is right.

You wont find a direct replacement.

Best bet is to take it to a local metal fabrication shop or call a mobile welder, and see if they can patch it for you.

Quality welds on a couple of 3/6" thick pieces of steel cut/bent to the right shapes and it will be stronger than OEM until it rusts through (once rusts starts it never stops, its like a flesh eating virus for metal).

Don't just would over it either. Cut as much rest or as you can, coat what you can work undercarriage paint or similar, then we'll the new piece in. (I know some of what you just painted will burn off, but what doesn't is pretreated)

I think this is the 4th one we have seen rusted in the same area. I would recommend an auto frame shop for the fab & weld work.
Unfortunately in the salt belt, it is very important thru winter to try to wash underneath and keep on top of rust as early as possible!
POR15 top coat is a good product once the areas are clean & prepped properly.
Even tho my 04 has been exposed to salt every winter, I have done my best to keep it rust free as much as possible.
Another area on my Jeep was the rear braking plates that had issues, and that was addressed early on.

Inspections & Paint work once a year in the spring, is best.

Look for a shop that does restorations. I had much worse rust repaired on my 96 XJ, bottom of the frame rails was rotted out, floors were gone...normal body shops/collision centers wouldn't touch it.

HoosierJeeper said:

Look for a shop that does restorations. I had much worse rust repaired on my 96 XJ, bottom of the frame rails was rotted out, floors were gone...normal body shops/collision centers wouldn't touch it.

Click to expand...

But isn't that how you know it's an XJ? By the missing floors and frame rails?