Johnvb,
Now that we can see what's up with the roof you really only have 2 options. First, if you were reading instructions on installing a Sensar III, the new Sensar IV antenna setup has mounting arms that are 6" shorter than previous versions but that's still not enough. If it were me (and it's not) and you thought you could make the modifications, I would cut the Sensar lift tubes down to the length required to get you an overall laid down length of about 3 feet. You would have the Sensar plus the Wingman for optimal performance. If you don't want to do that, I would return the Sensar and buy the Rayzar Air complete kit which has only one 13" tube plus the head and you would have plenty of room.