Oil patches on the right driveshaft or an oily right engine mount can be symptomatic of a leaky oil filler cap. As the timing chain rotates, it flicks oil onto the cap which can begin to seep out as the engine is running.

The oil cap seals against the rocker cover with a large plastic washer. Over time, this washer begins to deform resulting in a poor seal. Unfortunately, these seals are no longer sold individually but come complete with a new filler cap. A free alternative is as follows.

Remove the oil filler cap. You can clearly see where deformation of the seal has taken place (arrowed):

Using a thin screwdriver, begin to lift the seal away from the oil cap. Be careful that you don't damage the sealing face of the washer.

Peal the rest of the washer out of the cap.

Now simply refit the washer up side down! Compare the difference with the first picture.

Now refit the oil filler cap to the car. You will find that slightly more force is required to tighten it but it creates a much better seal and the stops the leaking.