Hi coop88 - good to join same time as another new Z4M owner!! Today I got up and just went straight out in it before it got too hot - smiling ear to ear!!
Incidentally one thing I learned already is how to do throttle adaption reset - key in and pos 2 for 10 secs, off 10 secs, on again 10 secs then start. Resets the throttle computer (I think thats the terminology) so it relearns again. Made noticeable difference and got rid of a little hesitation from idle so you might want to do that, since its free and involves no spannering at all!
Any photos of the E34? I love that shape - had an old 12v 520i one of the first of the E34's years ago - gutless, scruffy, high miler but loved it to bits and used it as a daily for a few years. Nothing compared to your 3.5 litre Alpina obviously but I still regret selling that.