Hi yes all z3 need to use the 20pin obd
This will be in the engine bay locations vary depending on model.
Then all you need is a 16 to 20 pin obd adapter plenty on ebay.
Join your 16 pin scan tool to the adapter the plug in under bonnet proceed as normal.
On my 2.8 m52 tu its near the fuse box but they all look the same .
Stephen.