I have a subframe brace the sits right in front of my differential that I use to jack up my entire rear with (recommended jack point by a BMW tech friend). I then place the jack stands under the jack points. Your M3 might be different than my 328Ci so you may have to look for a different spot. But just make sure you don't jack it up on the differential!
I also have a "button" up front where my triangle brace comes together as a central jacking point up front. I have to roll up on 2x6's first to reach that point with my jack. But after I get it up using that central point, I put the jack stands under the designated jacking spots as up front.
'00 328Ci Step + Sport & Premium Packages
BMP Design Front Strut Bar | K&N 63 Series Intake | LED Interior Lighting | M3/H&R Sway Bars | OEM Bi-Xenons + CCFL Angel Eyes | Smoked Turn Signals | UUC SS Brake Lines | ZHP Shocks & Springs