The Mini's rear subframe is rubber mounted. Polyurethane (stiffer, much longer lasting) bushings are now available for the rear subframe trunions. Cars manufactured before 1976 can use the same bushing, 2A5818-POLY, at the front and rear of the subframe, 8 per car.

The color of these bushes is purple.

Starting in 1976 (MKIV) the front trunnion bushing was enlarged, that bushing is now available in poly as C-STR639. These later cars use four (4) of each 2A5818-POLY and C-STR639.