And don't forget the RTABs. Rear Trailing Arm Bushings. May need replacement and either go with something like the PowerFlex or add the RTAB stabilizers.
And Shocks. Grond Control found the stock shocks lost about 50% of their dampning in 20K miles.
And of course, there are the unforseen issues.
'95 Alpine M3 LTW
'00 Dakar M Roadster
'02 Topaz M3
Red/White SRF #4 (Chassis 561)