I made the mistake of putting some damp shoes in a carrier bag in the boot and leaving them there, also, when removing the soft top cover thing from the boot it started to rain and water got on the underside of boot lid (it was windy).

Is the boot sealed? So the only way of drying it is going to be a dry day and to leave it open to air out? Water keeps dripping out the hinge tubes and it just sits there.

I've chucked a packet of silica gel in there but I'm not sure if that's going to do a lot.

 

There are air vents that run from behind the seats into the boot area, so it will get ventilated I guess.

It also gets very warm in there, so any water would happily evaporate away (combined with the above ventilation).

 

Hmm that might explain why the cabin windows keep steaming up!

 

so THAT's why there are vents behind the seats!

 

No, they are there to equalise the pressure in the whole of the car.
When you slam the doors or boot in a convertible, it is more an issue than a car with solid panels full of glass.
There is also a rubber 'pressure vent' in the boot (which can leak too).
Slamming anything might just burst the soft top otherwise

 

It's more likely that your soft top drains need cleaning

 

Sir, you have a drain fetish

 

I think it's leaking in around the ariel on the drivers side wing!

 

I'd say it wouldn't burst the roof, but pushes the windows outwards?

 

What makes you think that... puddle near the spare wheel (by the ABS wire grommet)?

If so I bet you its the roof drains or the rubber wiper (water guide) just up inside body in the rear qtr panel