Ron 61
Ron,
I have the four poster - similiar to Madmaxx. My ceiling height allows the GT40 easily and the standard family car below. Still lots of room.
I have seen the dry board removed and re boxed up similiar to a skylight opening. You generally pick up 8 - 10" here due to roof rafters/beams.
Another option I have seen when in Texas, was the use of a very large skylight that was placed above the screen and the roll bar.
This added the extra inches through the beam and a little extra, due to the raised skylight perspex section above roof iron - the skylight perspex dome.
.. there is always a way..
