A park assist system for parking a vehicle in a target parking space includes a first sensing system which determines whether there is a sufficient slot length in a target parking space in which to park the vehicle. In accordance with the invention, the metal washer, interposed between the screw head and the mounting surface formed at the bottom of the housing of the cover, includes two radial wings diametrically opposite working together with internal parts of the housing butting and preventing a rotation of the washer during tightening of the fastening screw. In at least one embodiment, the method periodically issues bundle version identifying signals to different nodes of the network. The collar is movable along the axis between first and second operative positions. Once the scroll wheel is rotated, the revolving shaft is driven to rotate together. The test circuit models a function of the integrated circuit device and generates the test result signal when the power input has reached a sufficient voltage to perform the function of the integrated circuit device.