In order to compete effectively in the automotive industry, vehicle manufacturers employ advanced simulation techniques to assist in their product development. Hardware-in-the-Loop (HIL) simulation is a technique widely used by vehicle manufacturers in the development and testing of their Electronic Control Units (ECU), which can number up to 100 in modern vehicles. To carry out HIL testing on the ECUs, accurate simulation models of the sensors and actuators connected to the ECUs are required. The models must also be capable of simulating in real-time to be suitable for HIL testing. This paper presents the development of a Jaguar Land Rover windshield wiper system for use in HIL testing. An off-line physical model is first developed and validated. The model is capable of being parametized to capture design updates quickly without the need for waiting for new prototypes, speeding up the testing cycle. The physical model is then simplified to produce a real time capable model of the wiper system. The simplified model has a significantly faster simulation speed than the off-line physical model. It is capable of being simulated in real time but is less accurate than the physical model. Genetic algorithms have been used to identify the parameters of the model. The on-line model is then implemented in a HIL facility to be used for ECU testing by Jaguar Land Rover.