X3 electrical problems

Help! My dealership seems useless. Driver's heated seat works only when it is all the way back, no power when the seat is moved forward for my shorter partner (seems like a simple bad wire - but they can't find it). Rear hatch releases as I turn off the ignition! Rear hatch release button works only intermittently. My feeling is that there must be some damage that occured during manufacture to a wiring harness that may have both the seat heating and latch controls as well as lighting controls(to account for hatch opening as ignition is turned off and inside lights come on). The dealership seems stymied. All they tell me is that no fault is showing when they run diagnostics. Anyone else had this?