bellow are just inside the right rear wheel. Tough to see unless the wheel is off and vehicle up on lift/stands. Find the AOS from the top side... bellows directly below. If you have had the AOS replaced once or your car is '00 or newer, the disc on the top of the AOS will be vertical not horizontal.
view from top side (courtesy of Mike Focke's pages)
shot of AOS w/ vehicle up on stands (courtesy of Mike Focke's pages)
what AOS looks like out of car: (courtesy of Mike Focke's pages)
even if bellow aren't leaking, doesn't mean AOS isn't bad as it fails internally too. Pull the j-tube (connects to the throttle body) and look for more than a misting of oil.
Here are instructions on how to R&R from Mike's Focke's page:
http://mike.focke.googlepages.com/airoilseparatorreplacement