Hello Steven,
Is the boot water in contact with any electrical junction boxes etc. or wiring? If so, this needs to be mopped up, all electrical components carefully dried with a hair dryer, before spraying with contact cleaner.
It would also be worth having the battery efficiency checked, before engaging in any more expensive diagnostics.
Perhaps you could let us know how you get on Steven.
Kind regards,
Gareth.
p.s. It is obviously desirable to fix the source of your leaks - usually the air vents, but a forum search should colour in the detail for you.