2009 R57

I was hearing a rattling when driving over bumpy roads and for a few weeks I couldn't tell if it was something inside the car or outside. I finally got under the car and found that the center two "legs" of the chassis brace had loosened to the point where the legs would bounce up and down and cause the rattling I was hearing. They are T50 heads - not sure, maybe M12 bolts?

Here is a link to a picture for reference of the piece I'm talking about: Rear Chassis Brace

I have the Bentley service manual that covers the R57, but this brace is no where mentioned in it.... anyone know the torque specs for the brace bolts? Much appreciated!