Just a quick update - I wasn't able to finish the project today but it looks good - I was able to locate all the wires (which are all the same colors as the E46 cabs, from what I've seen posted) and isolate them and I've programmed the TR7 module for 2 pulses and 12 seconds - what this means is that after I press "unlock - lock - unlock "- on the remote within 5 seconds, the top will lower for 12 seconds (plenty of time for the Z4 top). Tomorrow I'll need to connect 4 wires and I should be good to go!
I did change the project slightly - I decided not to bother with adding the top raising capability, at least for now. I just can't see myself walking away hoping my car finishes closing itself up.
Once I'm done, I'll do a more detailed write-up. There won't be any pictures - one of the glitches I ran into was discover my old digital camera is broken (I also lost my wire crimper somewhere).