Wow - this is a long thread. I'm not going to dig through it in its entirety, but I'm still trying to make sense of all of this the same.
Specifically, I had my car tuned with ESS stage 2 ~6 months ago. I have an '08 M3 - during the time of tuning, no one mentioned anything to me about a potential ECU update. I have to admit, I'm a bit annoyed that this detail was overlooked / not brought to my attention.
I suppose that I will now have to call the dealer and figure out what ECU version I'm running. Given that the car is an '08, it has the potential to old (and I don't recall BMW ever updating it [or at least letting me know that they had] during its check-ups).
If pre 190E, I will have to flash back to OEM, and then re-flash with the ESS tune? Gah, not fun.
Tom@EAS - how much would you guys charge for something like this? I'm in LA . . .
Ti Silver | ZCP | DCT | H8 160s | AA filter | ESS Tune (240E) | Akra Evo | MS Spacers
R.I.P. 2008 E92 M3: SSII | Speed cloth | LCI | H8 160s | 6MT | EDC | MS Stage 2 Intake | MS Pulley | ESS Tune (240E) | Akra Evo | MS Spacers | OEM GTS Wheels