I just topped mine up with oil today. I don't lift the bonnet very often but this time i noticed oil film just beneath where the cap sits. I cleaned it up, thinking nothing of it and then topped up with oil and refitted the cap.
Popped out for a drive and noted that the car couldn't display the level and the indicator was just continuously processing after reaching full operating temperature.
When i got back i lifted the bonnet and noticed fresh oil had come out from beneath the cap!
Having searched through posts on here i checked the O-ring to find it had kinked and split where it wasn't seated properly
I'll be off to the dealer in the morning to hopefully get a new seal. Beware in future that you should always check the O-ring is seated correctly before refitting the oil cap. Must be a common fault that they can work loose whilst the lid is being removed.
As for the level indicator??? Hopefully I've not over-filled it. I just put in about a quarter of litre as it was reading a little below the mid point of the level indicator.
Bob