These mirrors were originally designed to fit Mini doors that already had fixing holes provided by the factory. Depending on YOUR door there are three alternative methods of fitment.
1. On cars with genuine Rover plastic mirrors as fitted from about 1979, with offset fixing holes, a (13/16th" hole center) plinthfixing kit will be required. Two screws hold an alloy plate to the door and two self-tapping screws hold the plastic plinth to the plate. Kit part numbers are M90997 (LH) and M90999 (RH).
2. On cars with original chrome door mirrors, about 1970-'80, the torpedo type mirror will fit directly onto the existing chrome plinth. The fixing holes (2 1/8" centers) on the doors were horizontally level, not offset as earlier versions.
With the aid of a second person, locate a clear unobstructed position for the door mirror when viewed from the driving seat. Ensure that the fixing screws will not foul the window and that the mirror is not at the limit of adjustment in any plane.
Mark the selected position with a 3" long strip of masking tape to prevent the drill bit from running and scratching the door.
Place plinth as applicable in position as template & mark the hole positions. Carefully drill two holes using a 17/64" or 7mm drill bit.
Remove the masking tape and push both bosses of the plinth through the drilled holes. Insert the screws and tighten until the plinth is firmly fixed to the door. CAUTION - do not overtighten as this will strip theplastic bosses, resulting in a loose mounting.
Slacken the grun screw on the mirror stem and fit over the plinth. Tighten the grub screw until the mirror is firm, do not overtighten.
Adjustment is by the mirror glass and head. Do not overtighten the screws after adjustment. Only tighten the two crosshead screws on the underside of the mirror equally or you will damage the bowl.