#22 is the jack hold-down bracket for the E30 M3.
http://www.etk.cc/bmw/EN/search/selectGroup/47312/41_0328/41121919948The image below is from a 1989 325i Coupe I parted out.

#15 (pink circle) is the bracket attached to the spare tire well and supports the aft muffler clamp.
#16 (red circle) is the bracket attached to the outboard side of the support member and supports the forward muffler clamp.
#17 (yellow circle) is the bracket attached to the inboard side of the support member, hidden by the muffler heat shield and not visible. Actually...I couldn't find it installed on my E30 318is.

This is an image I took from BAVAUTO's website:

The bracket in the yellow circle and in the BAVAUTO image both have an angle cut on them which led me to believe it is part number 41111922407, aka, #17.
This is a picture of my car with the LH, rear wheel removed. As you can see, the forward hangar bracket is rusted half away and I believe this is #16, part number 41121919948.

Looks like I'll find out for sure when I order it.
