A generic bottom pad can be installed and the back left intact and working. You might try to find out if the original pad is being shorted by the hog rings first. I would use zip ties instead of hog-rings to reassemble. There are other threads on this. A small problem with installing the generic pad is that it probably won't be wide enough to go up the side bolsters but then you would also need to do some sewing if it was.

__________________
1988 325is (purchased new) sold
2004 X5 3.0 2005 X3 2.5
2008 X5 3.0 (new to me)