Hi Kane - I did the conversion on a 1997 2.8 which has a single stage system - successfully.
You have a dual stage, so the conversion is straight forward. The wiring connectors to the air bag are universal, so you won't need any connectors to be changed.Basically you will need an e85 Z4 wheel and airbag. The reason for the e85 wheel is it isn't a multi-function wheel, which would be costly and useless on a Z3.
The Z4 wheel is thicker, and smaller.
The adapter part you will need, I have.
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