Yay! Installed and working!
This Monday, I took all the info so kindly provided by all the posters in this thread and the parts I've been collecting for the past few months to a local car audio guy. He helped me put in my Becker navigation system and agreed to help with this.
After eleven (11) hours in the shop (!), all is well and my car now has option M454 "Tempostat" cruise control.
Some notes on what worked and what didn't:
- A - The connector for the Bridge Points is available from Porsche as part 999.650.320.22 or 999.650.321.22 (looks like the only difference is the cable gauge it connects to). Getting to the panel behind the relays and connecting this was easier than I thought, although it was time-consuming.
- B - You don't need the entire VW wire 000-979-010-E. These connectors are available separately from online retailers. Connection to the instrument cluster was really simple...
- ...but I broke my hazard switch / turn signal relay when pulling it out. Fortunately, I had a spare.
- ...and the bulb for the cruise control light was already installed, which was a surprise.
- C - As I couldn't locate an original connector for the additional cable that goes in the stop light switch plug, I used a regular 6.3mm spade. The trick was to drill out the mounting position in the plug for this to fit.
- D - More problems. The OBD2 plug female connectors that I ordered did not fit the plug installed in the car. I had to leave this unconnected. If anyone has the right female connectors, please message me!
- E - This bolt should go through the hinge in the accelerator pedal assembly. Removal was hard but reinstallation was impossible. I don't know why, but it just didn't want to screw in. I left it out as I'll be removing the pedal assembly for an upcoming project.
Overall, the process wasn't very hard, just lengthy. The hardest part was screwing in the cruise control control unit. I can still feel my back hurt from the time laying under the dash, trying to maneuver around the pedals and stuff to get at the screws.
If anybody needs parts A and B, I have some that I can send out for the cost of postage. If you have a OBD2 plug female connector pin, I'll gladly accept one.
Again, thanks to all the posters here for your support. You guys are great!