I have been told my oil leak is coming from the rear main seal. I have already had the sending unit replaced as they initially thought that was where the leak was coming from. I have been told that the main seal will be one of two ways on my car. The easier fix is if the oil pan and a portion of the rear main seal share the same gasket. The hard way is if they are seperate. How can I know which one I have? Additionally, any tips on what I should know to get this fixed would be greatly appreciated.