Initially the models were fitted with a small vertical rear flange that located within the boot. This was changed in 1986 to a 2 x 9mm horizontal flange. At the same time the DG18-19 baseplate text changed to DG18-19-22 followed by DG18/19/22/24/25 in 1987. A steering wheel was added in 1989. The baseplate text changed again in 1990 to read 18-19-22-24-25-38.