Well it's been quite a while so time for a bit of an update...
M5 - driving it when I can and trying to get from A to B as "efficiently" as I can whilst doing so...
540 - going really well. Just done a couple of good trips including the BMW Car Club run to Whangamomona. What a blast. Just recently I've painted the instrument needles again. A PO had painted them red, so I just re-did them in red again, would prefer the white but needle changing is a nightmare, and cluster even worse... Also put on a new steering column leather cover (that was a mission) and a new cluster surround. Got it all back together to discover a backlight bulb had blown.... out it all comes... Still, it all looks great now.
I've also decided to fully paint the 540 early next year so preparing for that, new rear MSII shocks whilst the interior is apart as well, rear parcel tray needs a re-cover.
740 - I've done a major gasket etc replacement on the engine and the oil leak has reduced considerably, it was the valve covers mainly, no surprises there. The engine was a real RTV special, why don't people just renew... But it appears there is still a minor weep suspecting the top oil pan gasket. I had thought originally rear main seal... However I happened to scan the transmission one day and a code for slipping lockup clutch is up on the torque converter. So I'm going to get my spare msport TC refurbed and sometime in the next few months I'm thinking an upper gasket, RMS, and TC changeout is coming up... I haven't really noticed any symptoms driving it, but now I know the code is there, my mind is playing silly buggers with me...
Other items I've changed on the 740 are the rear door rear rubber trims, transmission mounts, trans fluid and filter (code was up before this), fuel filler hose, centre console rear controls, and a new LCD screen for the Bordmonitor. Being a newer screen it is compatible with polarized sunglasses so that is a great improvement, as well as generally looking heaps better.
Will be looking to do a bit of paint on the 740 myself over Summer if I can find the time...