If you have a custom tune provided as a file to be loaded onto your X3, or one that was loaded onto the device before you bought it, the User Adjustable options will not be available unless the creator of the tune file enabled them--most do not as they do not wish to be liable for a user messing things up and damaging the engine.
BAMA or any SCT shop can provide a tune with the rev-limiter increased (or decreased) from the stock 6050 RPM of most GTs. You should also be able to elect to load one of the pre-programmed "canned" tunes, and at that point answer Yes to the Adjust User Parameters prompt. This may not be the exact process as I have not used an X3 in years...
- 2003 GT, UPR X, FRPP 24lb/h, Magnaflow, PP 70mm TB & plenum, Delta Force tuned,
Steeda UDPs, Ralco flywheel, RAM HDX clutch, 3.73s, 262 rwHP/305 lb-ft.
New ride (7/1/2013) 1998 Mercedes SL500-5.0L 32V VVT 326/347 HP/tq