Hi Fuzzy. The intermittent Amber Oil light is a faulty sensor,I had mine replaced at approximately 132,000 by my BMW Specialist/Independent,not an expensive job as I recall.
The intermittent faulty reverse sensors on my 51 plate 330i Automatic has been diagnosed as a damage wire,possibly cracked outer plastic case and due a rewire shortly.
I recently had the transmission service carried out by the same BMW specialist,not cheap but less costly than replacing a buggered automatic box.
The car is going in on Wednesday for a new black rubber frame around the windscreen - circa £110.00.
The car is now at 135,200 and running as smooth and sweet as whipped cream.