Folding the roof down incorrectly can crease the rear window and/or quarter lights with the potential effect of splitting those windows. At the very least the creases are likely to diminish your visibility.
Many people 'cheat' on the rear window by unzipping it and laying it down first, this certainly helps extend the lifespan and is better than introducing a crease, but it doesn't help those rear quarters.
I would like to thank Jay Human for allowing me to reproduce the following article, displayed on his website, which graphically describes the correct method of lowering the hood.
Step 1: Detach The Hood From The Frame.
The hood is attached to the middle frame bar, via a Velcro strip (see Fig 1.0). This can easily be detached.
Also unclip the poppers attaching the hood to the car body and release the front locking handles from the windscreen surround.
Note that the bar can be pushed back with the hood attached but this will introduce a fold, aside from making correct stowage impossible!
As the hood is no longer attached to the middle of the frame we can effectively lift it off the frame - see Fig 2.3 and lay it over the rear deck. This allows us to fold the frame correctly - no force is necessary for the frame to be folded quite flat.
Step 4- Stow The Hood.
With the frame safely stored and the quarter lights folded in you can now flip the hood over into the storage compartment - see Fig 4.0 which is viewed from the front of your Triumph TR7/8 convertible.
The window will be flat, avoiding any creases. The entire stored roof itself is actually more compact than had you left the hood fixed to the frame; this in turn means that the cover is easier to fit, with no unsightly lumps (see Fig 4.1) to mar the terrific lines of your Triumph TR7/8 convertible.
My thanks to Jay for a very detailed description.
(Should you require the label on the sun visor relating to this please contact Brian Ridley-Jones Ed.)