Help identify this part
 

i am new to all this. I drive a '94 Buick Regal Custom 3.8, my rear struts have been very bad for a while now and ive been driving it waiting to come up w the money to fix it. Yesterday on the highway suddenly each time going over a bump my car seemed to steer to the right independently of the steering wheel (different from the bouncing and swinging from the bad struts), i made it home and took it on the road this morning for another feel, not far from home, i suddenly seemingly lost my steering, not completely as i was able to drive slow in the breakdown lane and carefully get it back in my driveway. once back in my driveway i noticed my back left wheel was turned/tilted at an angle. i looked under and saw THIS (will attach pics). SO MY QUESTION IS: What exactly is this busted part? Is it the rear axle? i wouldn't have expected the axle to be hollow... also the only thing i did differently yesterday was take the car thru a car wash for the first time, car was had an undercarriage rinse as well, probably an irrelevent coincidence but i thought id mention it. Anything you can tell me will be very helpful, like i said i am a beginner with car stuff but i am handy and would like to fix myself as much as i can
https://cimg5.ibsrv.net/gimg/www.bui...b469a276a6.jpg
https://cimg6.ibsrv.net/gimg/www.bui...483fbed5c4.jpg
this busted peice connects to the other wheel in the rear

What you are seeing is the result of salt action on the metal of the vehicle. That part of the vehicle should be replaced.. Common problem in areas where rust is a problem..
May need to get replacement parts(whole axle assy) from a salvage yard. Don't know if new are available anymore.

Ya it is a axle that has the two wheels connected and yes they are hollow for weight saveings and fuel econemy.

they don't carry a lot of weight just keep the rear wheels alinged..

I would check salvage yards for the part. MFG and dealers do not have to carry over 10 year old parts.

:D Al

control arm / assembly
 

I was told this is a Left Forward Rear Lower Control Arm. I realized it doesnt go straight to the other wheel, it bolts up in the center then another arm goes to the other wheel, theres a set of them on each side of the spring. does anyone know what i might call that whole assembly? im considering whether it will be more efficient to replace the whole assembly if i can find it whole

I believe if you were to call it a "Rear axle right side strut to body assy" they would have some idea what you are talking about.