2009 E90 Sedan Automatic 95xxx Very well maintained. I have a very small engine oil leak at the far rear passenger side of the motor that rolls down the corner of the block (facing the tranny) and then gently drops oil right on the exhaust (very annoying). The valve cover gasket is bone dry, the oil pan gasket is bone dry, the oil filter housing gasket is bone dry, I also cannot see anything leaking from the VANOS solenoid or sensors, plus all of these things are at the front of the engine and this leak is at the very rear. Any ideas on where this leak might be coming from? Rear main seal?