By the way; the rear transmission tunnel is a panel of sheet aluminium, not cast.
Sorry Peter that's not correct.
The rear most section of the transmission tunnel where it joins the back board is an aluminium casting.
It's unfortunately quite common for the propshaft to catch on it. It normally catches on about the 10 o'clock position viewed from the perspective of the axle. A panhard rod will normally restrict the sideways movement enough to stop the rubbing, and is a relatively cheap fix.
Simon @ SiFab.co.uk