Whoever thinks it can done in 2-3 hours is very wrong (FWD, NOT RWD car), sorry but the subframe must be lowered, driveshafts removed, steering and front suspension disconected, trans completely removed to replace the REAR MAIN crank seal. The labor to R&R that trans alone, not including any seals is 9.5 hours (add 1/2 hour for turbo) according to either Chiltons or Motor labor time guides which is what most shops quote their labor times by. That's also a "suggested" rate, they can add more time to that due to age of the car, rust, other possible needed/related minor repairs, etc if they want to. They're then adding more time to R&R the flywheel and seal itself. There's NO other way to do this as I've done it myself many times.

Now, yes....adding 2-3 extra quarts of oil will blow that seal out. That engine takes about 6.5 qts with filter to fill it to the top of the dipstick mark. Why would you add more than that?

Those seals normally last longer than that for most people but I've also seen them leak sooner too so there's no "rules" as to when it's going to leak. Next time, don't overfill the engine and be sure that your flame trap and related hoses are free flowing, no restricted hoses either.