I'm thinking about doing a straight trade for a 2004 Civic Si for a 2001 Saab 9-5 Aero. I've confirmed the MID is working properly, is there any Saab specific questions I should make sure to ask? I have never owned a Saab before
You will definitely want to look into the sludge issue that is common in pre-2004 engines.
I believe that most people around here are recommending that you have the oil pan dropped and cleaned if not before purchase, immediately after. Mine is a 2004, so I'm not real familiar with the problem/solution.