when I bought my 944 about 500 miles ago, it had no oil leaks. Now each day there seems to be an increasing amout of engine oil leaking from the rear of the engine. I can see a bit of oil near the head/valve cover joint but don't know if this is where it's originating. Engine runs good (especially after new platinum plugs and cap/rotor and K&N replacement). I just don't understand where it's coming from and why it's increasing in volume. Any ideas?

 

You need to do some more searching. There are a lot of places oil can leak out at the rear. Which could include:

Rear cam tower gasket (passenger side engine leak)
Cam tower gasket (passenger side engine leak)
Lower rear balance shaft o ring (passenger side engine leak)
Upper rear balance shaft leak (drivers side oil leak)
Oil/Air seperator o-ring leaks (drivers side oil leak)
Rear main seal leak (centered)

All can drip down and run off the back center of the engine and mimic each other, so look close. If you see oil coming from a gasket, replace it, and see if it goes away. If not, look for another gasket and do the same.