I have the same phenomena on the passenger side and quite a lot of oil along the bonnet, windscreen and the whole side.
Reason:
The right cylinderheadgasket is not 100% "dense".
The hotter the outside temperature is the more oil is on the M3W.
At the first service the garage used 20W60 (a bit thicker) oil to solve the problem. It didnīt really work out.
Less oil was leaking but still it was leaking.
So next time they will check that out and maybe change the gasket.
Till then Iīm always cleaning the right side after every ride.
Hope that info helps...
