Here's the 'Mohair' offcut:
Very little science to this. A simple rectangle with the rear corners sliced so they don't protrude. It's single thickness, so a bit flimsy, but I'll look into that again when I get some more aerosol glue.
The front corners are held up by short straps onto the hood side rails, using one of the studs each side normally used by the hood when it's up.
I keep a small stock of hood fasteners (for emergency use), so this has cost nothing.........well, today, anyway.
Compare the next two photos with those above without the half-half tonneau.
