Special Tuning hit upon this idea to stop the driveshafts breaking on their rally cars. Do away with the large circlip groove where it broke and weld a spacer on the shaft to locate the CV joint in position. The works department also reduced the steering lock to eradicate over stressing of the shaft on full lock. These were for the remote type box or original Cooper S variants.
See
C-BTA1268 for rod change gearbox type.