the wiper motor/linkage is located at the n/s baulkhead under the windscreen. These cars (vw sharan, seat alhambra and ford galaxy) have a common fault with the wiper linkage at the n/s spindle as water runs in and rests on the spindle resulting in corrosion and eventually seizing the spindle. usually if you catch it early enough it doesnt burn the motor out, as for doing it yourself it isnt difficult just a little tight to gain access.