Well I finally looked under there and the thing seems simple enough. Odd that I never noticed that cable before! Giving a little tug on the cable I noticed that with a little pressure the latch closes more but with a little more pressure it begins to open, I suppose that's why the cable's tension has to be just so for things to be in working order.

Nix

The latch is designed so that if the cable breaks...the lid will release. Adjust the latch/cable to have a slight tension on it when postitioned, and when it's correct put extra cable stops (cylinder-type clamps found at the local auto store) to back up the factory setup.

Good feature on a rear cover, but unfortunately the hood(bonnet) is little more difficult. It's a good time to check how to get to the mechanism, NOW, before the cable breaks and you have to drill a hole and fish in the dark forever.