How many wires are on the driver side wing?

SOURCE: Nearside wing mirror on 1998 Z3

you need to take door trim off door and a triangular peice of to ge to the bolts area usually a #10 mm just tighten

SOURCE: bmw e46 electric wing mirror wiring diagram

your mirror control switch has 9 wires.,your drivers door mirror has 5 wires color coded .from your mirror control switch to your drivers siide mirror / 0.5 black .0.5 brown. 0.5 brown. 0.5 black. 0.5 black.
your passenger mirror wires are 0.5 blue/black .0.5 blue/grey. 0.5 blue/white. the passenger mirror has a ground cable 0.5 brown.
the passenger mirror wire 0.5 green/white connects to a 5amp fuse/F25 onto F31 5amp to a wire 0.75 green/yellow.back to the mirror control switch.

SOURCE: correct procedurer for removal of door panels to remove wing mirror for replacement

three fixing screws under door pull two on the handle and one under the electric door mirror control

SOURCE: X5 wing mirrors wont stay retracted

the micro swithes inside the mirror unit(s) have probably broken inside

SOURCE: removal and replament of a 3 Series BMW E46 1998 saloon wing mirr

On the inside trim, you can remove screws that are by the door handle, arm rest, under door and side of door and then gently pull back on the panel as there will also be retaining clips attached and you don't want to break them. You'll need to lift the door panel upwards in order to get it off the window ledge. Then you'll need to manipulate the panel and disconnect the door handle linkage from the door handle and disconnect the wiring for your controls. Then you can access the bolts that secure the mirror onto the door