my car does this, it was headers rubbing against the body. the lower part of the header near the x-pipe. the engine would shift and cause it to rub. only on left turns.
probably not your problem, but it's quick to check.
2002 e46 M3 - Jasper Motor Werks Stage 3 kit (JMW Re-flash, JMW Headers, JMW X-Pipe), H&R Springs