Nobody has mentioned it yet, but the first thing I would do is check the flame trap and make sure that it's not clogged If clogged, it can build up pressure inside the engine and cause oil to seek the easiest exit - usually the rear main and blow-by around the oil filler cap that shows as oily crud on the valve cover around the cap. If it's leaking like a sieve, of course, it's too late for anything but the seal.

Volvospeed/Bay 13 has instructions. Trap costs about $3.00 and takes maybe a half hour to an hour the first time you do it, less after. If it's really bad, you may want to clean up the plastic piece that holds the trap, just a toothbrush and some gasoline works. Good idea to replace it every time the timing belt is done, just as a reminder.

I found a guy to do a rear main for $600, everybody else wanted $900-plus. He came highly recommneded by other Volvo owners, but he has since "disappeared". He worked out a gas station and one day was just gone, I'm told.

As for other things to do, power-flush the trans if yoy haven't already. IPD sells a kit for about $10-12, they just buy the fluid and you should be done in an hour. Little mechanical ability is required for either of these. Or you could a shop do it, should cost around $70. including fluid. There's loads of info on this board and Volvospeed.

Good luck...