Most decklid latch trouble centers around trying to keep the lid from shaking sideways and chipping paint off its rear edges. The latch hook is die-cast zinc or aluminum, and its easy to file the notch deeper so it doesn't fly open. I did this in the mid-'80s after losing control of the lid on the road a few times and its still holding today. A slightly stronger latch-spring from your local hardware store helps, too, and it will likely be zinc-plated for rust prevention.
Wings always require stiffer gas springs than stock. Some vendors will not sell gas springs rated over a certain strength for fear of bending the roof mounted hinge brackets from the added pressure needed. Changing the gas spring leverage or substituting Ted Michell's 'Vader' decklid mechanisms is the real fix here, I think.