4x Omega's - 300k+ miles covered. Number of rear discs replaced = 0
Well whoop di doo...
Mine is on its third set of rear discs in 255k, so go figure...
Sorry, fourth set. Plod put a set on it at about 75k 
Think some people need to read road ahead better 
That's appalling wear rate for rear discs
I make that about 85k per set. Thats not bad. Not everyone has easy motorway runs. Also remember that V6 traction control does give the rear brakes a good thumping.
Once they are at the minimum thickness, you do really need to change them. The brake designers (the wear limits are likely to come from the initial disc supplier, based on their expertise and calculations) don't just specify it for fun. Its not just heat dissipation, its the structural strength of the disc. A failed brake disc is quite spectacular, and you won't get prior warning.
You could argue that tyres still have plenty of tread at 1.6mm, but the laws are there for a reason
