I have just restored the self-parking to the rear wiper on my 2000 Focus 1.6 and you might be interested in how to do it.If the wiper moves at all when you switch it to the interval wipe, the timer unit is sending the pulse to the motor, which starts the wiping action, The rest of the wipe is controlled within the wiper motor by a circular contact plate with a section missing. This missing section stops the wiper motor at the self-parking position by interrupting the earth contact. To fix it, make sure the wiper is parked where on the screen where you want it tp park in future. Remove the wiper body and strip it down. Fairly simple, but you have to remove the rear door trim to get at the fixings. The 4 screws are fine, but levering the clip fixings are tricky - take it easy or they might break. Remove the wiper arm to allow the removal of the motor/gearbox assembly. Note the washer and small 'O' ring position. Mark the position of the nylon geared ring againt a marked point on the housing. A spot of paint will do. Make sure the marks line up on reassembly Remove the screws (small Torx) from the gearbox cover plate and drive out the wiper shaft with a wooden mallet. Note the small nylon cap and the wavy spring washer positions. My circular plate was covered with a mixture of rust, dirt and grease!!. Clean the plate with wet or dry until smooth and clean. Clean and grease the gear teeth and all bearing points and reassemble everything. I didn't grease the cleaned up plate but doing that might help prevent the plate corroding again - up to you. Good Luck - it is worth the effort to have the wiper parking properly again!