Get a good battery and:
- Supply ground to your engine metal part (transmission is OK)
- Supply positive cable as below...
Under the car near LEFT FRONT tire, there is a positive terminal feeding the starter motor.
This is the area just aft of the driver's left foot (but under the chassis).
I don't have a photo on the X5, but this is the photo from my 1998 528i M52 car.
This will allow you to open the trunk in an emergency...
