Seriously bad oil leak
 

On my 1999 S80 T6 I just replaced the camshaft seals and timing belt because oil was leaking all over the timing belt cover. No leaks there anymore. I also replaced the flame trap and dipstick seal although upon inspection all the engine ports were clear.

So now after driving for a while there is a steady drip of oil coming right down by the lower motor mount between the transmission and oil pan. It leaves a large puddle after a day at work and then a steady trail while pulling into the driveway. Any ideas what could be leaking down there besides the rear main seal? I lose like two quarts a week. :(

Did you replace the rear camshaft seals also? Or only the frontside.
Could be a leaking seal tracking down to underside of transmission bellhousing area near the weephole.
Oil from the weephole itself is likely the RMS.

Oh man thanks for suggesting this. Earlier today I was browsing craigslist and nearly responded to someone who bought Volvos.

I only replaced the front seals by the timing belt and ordered that pound in metal cap but never installed it. I left it off in case of having to redo the timing procedure. Well when I removed the old one some oil did dribble out but it wasn't filled up or anything but now it looks like without that cap oil was almost spraying out! Oil is all over that side of the engine. I'm going to order new seals for that side and another metal cap.

Quick edit. Is that metal cap the seal itself?

Its only a cover cap. Keeps dirt etc out.
Blowing seals can be caused by your PCV system requiring replacement or servicing.
Do a glove test over your oil filler opening to see if it inflates.That indicates excessive crankcase pressure which loads up the seals and they leak oil.
It should suck the glove inwards with a vacuum if its healthy.

The PCV system is good. When I took it all apart everything was clear.

FCP is showing one part number for rear cam seals. Volvo S80 Camshaft Seal Parts | FCP Euro

So its used on both cams?