Austin Rover introduced plastic bumpers in body colour with the 1983 Austin Maestro. It was decided for absolute colour match that these should be processed with the car. This restricted the selection of materials to those which are stable at 135°c. The design of the bumper to achieve weight savings was totally in P.B.T.P. to meet 4 Kph impact tests and required careful attention to fixings to recognise the expansion that takes place during the processing.