Karl,
For our original Newell window shades I drilled and screwed up into the roller about 5/8" from the right end. There is a post somewhere on here that gave me the right info on this fix. I don't know if this will work on the front window shades.
The gist of the fix is to screw the plastic inside to the outside part of the shade with I think was a #8 screw.
I never updated this thread but just this morning I had my upholstery guy come and take measurements of the front windshield area. I am having him make two large blackout screens in light gray to match the dash covering along with the side front windows. I could remove the roller shades and get motorized blinds but these still work. The motorized cellular blinds would not fit well with the existing roller shades if I tried to keep both systems. In the end, this was my solution [removable foldable window shades] and it will work for us. I wear prescription deep limo tint glasses for driving. The sun does not affect me whatsoever with them on and they adjust for cloudy conditions. Without these on, I get migraines as I am very light sensitive. I do like the black out lower portion of the existing screens but we do not like messing with those 30 year old blinds in an attempt to preserve them.
Simon whatever works works, our curtains are in pretty bad shape every time we close them the little balls come out of the track but it's on our list to repair this somehow someday, we've been told it takes 2 years of work to get your coach in order were getting close to half of that done we hope.
We are at the 2 year mark. I removed the curtains since we wanted a cleaner look. The upholstery guy wanted to make new ones but I love the clean look without them.