I just purchased an unfinished MGTD Ford Kit. I am beginning the process of gathering of few of the required parts. On page 58 of the directions it indicates the use of a VW wiper motor assemble. I went to the P & P yesterday and removed a complete assemble from a old style VW BUG. The distance between the dimples on fiber fab is about 151/2″ the distance on VW the wiper post is about 201/2″ So what part of the equation am I missing.