Good stuff Jason. Funnily enough, changing the gearbox oil is on my list for the 9-5. Though the preferred method for those that have more time on their hands than me appears to be a partial flush ie drain, fill, run, drain, fill, run etc. Roughly £120 worth of gearbox oil. Probably why I haven't done it yet.
The 9-5 also has a gearbox oil dipstick which is a new one on me but does make filling easier.