What is the most likely cause of a heavy oil leak? It's in the middle and just behind the the steering gear. There's a line of oil on the ground 200 ft back. I pretty sure it not the pan plug.
i assume the oil color is dirty hence it should be engine oil, and not gear oil, or power steering oil, or brake oil....
oil leak could be tricky,
how ever below is a list of what could be the problem
crank seal
camshaft seal
lower rear engine seal
sump gasket
However my advise to have underneath the car degreased and steam cleaned then dried and inspected, that will definitely identify the leak... good luck mate.