Please consider taking your car to a professional. Judging by the pictures, you may be doing more harm than good. A body shop can remove the wing, replace the galled bolt, and apply new seals and RTV sealant to stop future leaks. If you continue doing this work yourself, please make sure you round off the edges of that hole widening job. The little sharp edges you created, if not smoothed over, can birth some ugly spider cracks on your trunk lid.
Also, for what it is worth, when I ran my auto detailing business, I would deal with interior moisture by using an athletic sock filled with cat litter (zip tied at the top to keep the litter in). Easy and cheap. Just be sure to get unscented litter!
2007 Exige S - Storm Titanium
1961 Austin Mini - restoration and turbo install in process