Another complication! It seems that early 2012 cars have their sensors held in place by M8 bolts. My car is June 2012 and uses a M6 bolt, so it looks as if the M8 mounting was short lived. It's not a big deal to file out the mounting hole in a replacement sensor to 8mm but is something to be aware of. By the way, don't attempt to drill out the hole in the sensor to 8mm as you'll find the metal insert just spins in the plastic housing.
I'd be glad to hear if anyone has a car later than mid 2012 that also has the M8 mounting bolt even though it would prove my theory wrong!
