This is one of those threads where it is very frustrating that the poster has not filled out their location in the profile. If you are paranoid about someone finding you and stealing your car, then at LEAST post your state, province, or section of your country. Including which country might also be helpful.

The reason I would like to know where you are is so that I know the climate in which this is happening. In very cold weather if a vehicle is not driven regularly for a period of time long enough to heat up the oil and boil out the moisture, it will look like this.

Under such conditions the oil should be changed more frequently, at least in the Winter time.

Now, for all I know, you are in Australia and it's the middle of the Summer which would indicate something else. But how can we know?