Your car sounds amazing, mines booked in for its service at FJRS very soon and I’m toying with the idea of going for the mountune upgrade as well at some point. I’ve recently had works done by them on my mk2 st focus, they did an amazing job and won’t put my car anywhere else.
I’ve had all three versions of the RS focus now, really wish I’d kept my mk1 RS though, if I could have afforded to at the time. The reason for changing back from my mk2 to the mk3 was due the shell seats aggravating an old back injury, the drive was amazing, so different to the mk3. I didn’t want to mess with the car’s interior as it was a standard, mint example and only had 26k on it, so I let it go to a fellow enthusiast. I may get one again at some point but a more used, good condition example and then swop the front seats out for a type I can get on with, that is, if I can save that much up!! 😁