If you were using a BMW Y cable before (i.e. you don't have the tech package), you'll need to buy a lightning to 30 pin adaptor. Otherwise you can just use the lightning cable for most functionality or BT audio
BMW X3 (F25) xDrive20d SE . . titanium silver . . titanium front grille . . 309s . . xline . . xenons . . black leather . . alu trim . . professional multimedia package . . dynamic package . . climate package . . electric seats . . folding mirrors . . servotronic steering . . DAB radio . . business speakers . . sun protection glass . . split rear seats . .