I apologize if this is already clarified somewhere, I looked first.
My primary concern is the correct process for Write Entire, VIN and VATS so my stock radio and OnStar still work afterward.
I'm happy with my 'stock' tune, but wouldn't mind playing around with a GMS1 image (I've read it behaves differently, I'm okay with that.) Unfortunately, I'm not sure what the correct process is for flashing a GMS1 tune out of the tune repo. I assume people have done this successfully on the LNF (a 2008 Sky Red Line, in my case.)
What is the process, if not this:
1. Know how to tune your car.
2. Read stock program from car, back it up. Cost: 2 credits.
3. Locate a tune file in the tune repo for your exact year, make, model, engine, trans-type, etc.
(For my 2008 Saturn Sky Red Line 2.0L Automatic Transmission this sorts out as 1401928147 from RotaryPiston.)
4. Pull a number of similar tunes and compare them for inconsistencies, you will find inconsistencies. See Step 1.
5. License Tune File (required to flash?) - Cost: 2 credits.
6. "Write Entire" (with incorrect VIN) to Vehicle.
7. Change VIN after "Write Entire" completes.
8. Relink VATs after "Change VIN" completes.
9. Turn on vehicle, Radio and On-Star (if equipped) to verify everything is working.
10. "Read" program back off car, with corrected VIN Cost: 2 credits.
Total Cost: 6 credits.
Thanks in advance!