Three weeks it has taken to get a definitive answer and its "YES" you will null and void all your warranty if you fit the RS ECU even if they fit it.. Sorry if this has already been discussed in other threads but I still cant believe it.
If it wasn’t the fact that the Cup is in again for warranty work (banging on acceleration….engine mounts??) I would get it done………. I’m off to look @ the autotrader, I’ve had enough…….deep breaths...calming thoughts.........