They call it a bulkhead in the part catalog. What the part actually is is the central part of the front suspension (for RWD vehicles). The front arms connect to it, the front bumper goes on the bottom, and the flat plate of the chassis attaches to the angled part. I've had a few break in the past from rough crashes and stuff.

You might have to ream the holes a bit, but it printed just fine by itself. I recommend using a tough material, like nylon, but I bet it would work for a while in ABS or PLA.