Is there any guidance on how to repair this component? It locks initially then springs open straight away.

 

Sounds like it needs to be adjusted I'd imagine. Just a guess without actually seeing it myself but it seems like the locking action isn't tight enough. When the levers are locked there's a good amount of tension on them from the top as well as the fit itself; I'm assuming that's what keeps them engaged. The latch should need to pull the top down flush. What year is your car? The earlier AP1s had issues with the soft top strikers not fitting tightly enough; I think that lead to wind noise and a not tight seal, but I don't think I saw anywhere that the latches would disengage.

You can try shimming the striker portion on the windshield frame with some washers, that should make things a little more snug.

 

Thanks for your input. It's an 02 S2 I bought in 05.
I will be honest, I have kinda neglected my S2.
Shame really. But I just realised... about a year or so ago, I got a windscreen replacement on insurance as it was cracked. They didn't really fit it properly and the left-hand side (which is the side where the latch problem is) stopped working (i think) after that. There is about 3/4 cm gap between the bottom of the screen on that side and the edge of where it meets the windscreen, which would explain the lack of pressure when it locks/latches.
At the time I didn't think to complain but now here I am in this situation!!
It's almost certainly down to the bad craftsmanship of the windscreen fitting.
I will now phone Hastings Insurance and try to get them to fix it. (I also have a rip in the roof because of this.)
Again, any advice on how to play this with the insurance would be GREATLY appreciated!!!