Great, now what.....
 

Well, after a bit of spirited driving today on the way home from work, I hard a weird noise like a "woosh" noise at about 75mph. It was having trouble accelerating after that. Took it off the highway and onto back roads the rest of the way home. At a dead stop, it runs rough. It won't stall (well, hopefully not yet), but runs rough. No check engine lights or anything, which is odd, as I know Volvos throw a CEL for a gas-cap not on tight enough.

I'm hoping my turbo isn't shot. Can anyone maybe offer some advice to what may be my problem?

Arg, it's just been one thing after another with this car....

probably blew off a vacuum line.