AnttiO said:
GuidoK: Do you have some kind of diy for rear bush replacement? Or it is similar as E46.
It is similar to the e46.
Do you mean the rear trailing arm front bushing or all the bushings from the rear axle? (19pc in total incl arb, diff etc)
For the rear trailing arm front bushing:
If you polybush, the only tricky thing is to get the stock bushing out. Get a generic bushing extractorset or the special bmw tool. The new ones pop in by hand (apply coppergrease, they act like a bearing)
If you use stock bushings, you have to put the new ones in at a certain position, and apply preload when putting it in the chassis, otherwise it sits under tension on stock ride heigth and will fail prematurely. See TIS for instructions.
For generic bushing extractor sets you can use something like this:
http://www.ebay.co.uk/itm/UNIVERSAL-PRESS-AND-PULL-SLEEVE-KIT-BUSH-AND-BEARING-REMOVAL-SET-UK-SELLER-/251355449740
http://www.ebay.de/itm/Silentlager-Abzieher-Satz-27-tlg-Werkzeug-Abzieher-Ausdrucker-Zug-NEU-/400786215973
You have to work out what's cheapest to ship to finland etc.
For complete polybushing your car I have a spreadsheet with (some of the) possibilities, but it's a work in progress:
http://audio.home.xs4all.nl/zooi/z4/bussen/z4%20polybush%20list%20V1.0.xlsx
(still only z4, no z4m)
There is some nice new stuff on the market, but I haven't had the time (or motivation

) to finish & maintain it and open a topic etc.
It basically only addresses powerflex&strongflex, with some alterations.
I made this for a guy from zpost.