That's not a bad idea, it really doesn't need such a hard latch. My last mower didn't have any latch, but the hood was metal (most of it, anyway). I do transport the tractor a handful of times each year on a trailer - facing forward so the wind isn't an issue - and I'd be worried about the bumps causing the hood to bounce around. I do have a pretty rough yard, the plan is to smooth it out as much as possible over the next few years, and every once in a while I forget a bump and get bounced pretty good. If I come up with a decent idea I'll post it up.
I picked up the parts yesterday for the low fuel indicator install. Not sure if I'm going to tackle that here at home in the cold this winter or bring the machine to the shop where it's warm once the winter business slows down a bit. I'll try and get some pics of the process, it's not a very expensive add on IMO and should be a handy feature to have.