Ultrafail:
Was driving to work with my confidence restored. 50mph on a single lane A-road, flashing PRNDS all of a sudden, loss of power, traffic behind, traffic in front. Hazards on, coast to the side of the road, onto the pavement, power off.
Key won't come out. sh*t.
Try to turning the car on again. No engine turn, just that horrible flashing PRNDS. Doublesh*t.
Eventually after much cursing and pusing of the button on the knob, the lever locked into P and I was able to restart the car.
Gently get back onto the road and start making my way to VW, having called work to say I'll be late.
Whilst I'm driving along again, PRNDS flash, car coasts, but then picks up all by itself again. Behaves itself all the way to VW, and no CEL.
Presume it's still a problem with the position sensor on the lever; will probably warrant the replacement now as it could've been quite hairy if it'd lost power on the motorway.