Originally Posted by Diseasel300

You definitely have more than just a rear main leak. A leak of that magnitude from the rear main would have a constant thin stream of oil draining out of the car when the engine is running to lose that quantity of oil that quickly.

How's your engine blow-by situation? It's possible you could be pushing oil out if the blow by is bad enough or the breather tube is blocked up.

Otherwise, check the turbo. If you've had a seal failure, you can lose oil surprisingly quickly. If you've got oil spraying out the tailpipe, it's on the turbine end and yes, it can wind up on the rear surfaces of the car if it's spraying out like that. It could also be your oil leak that you're seeing, possibly dripping from an exhaust joint or the downpipe (which runs right next to the bell housing).