I called into the local trans place today. Would cost $250 - 300 depending on how much fluid they have to use to flush it clean. They would also hook up to the
TCM and check for errors.
I'll see how much the fluid is going to cost me. I doubt that I'll keep the car long enough to do it a second time, so it may not be worth sourcing the sockets for the drain and fill plugs, and buying the fluid.
Then there is the whole issue around which fluid to use... Seems to cause a lot of angst among Saab owners in particular.