Don't quote me on it, but I believe as long as the tuner is fully unlocked you should be able to clear trouble codes. I don't know if you'll be able to change features like the rev limiter and speed limiter without having the tuner mated to your car.
I think an X3 runs around 350-380 with three custom tunes. Not sure what you can get the used one for but it might be worth it to save and buy new, then you're guaranteed to be able to use all the abilities of the tuner.
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB