I know you're not looking for alternate solutions, but the solution that works for my lexus key is a $5 dry bag. Little bag, about the size of a ziplock sandwich bag, that has 3 levels of heavy-duty ziplock seals that roll up. Never had a problem down to 91 fsw (my deepest beach dive, which is the only time I need to use it, since keys stay dry up on the boat just fine). As with any dry bag, test it empty with a piece of kleenex in it first to detect any slight leakage.
Another option, sometimes, is to find a friend who doesn't have an electronic key, and lock your keys in his car. A touch more risky, but not much.
Do a search on otter box here and you will find many reports of them leaking. I think heavy duty (think can light canister without the battery) is going to be your best bet if you simply must bring largish object down to depth and keep them bone dry. A cheaper solution may actually be flashlight without without the batteries! But any case, even a good quality one, can leak if you're not excruciatingly careful: witness the horror stories of flooded cameras in expensive cases that are DEFININTELY designed to go to depth.
Another option, sometimes, is to find a friend who doesn't have an electronic key, and lock your keys in his car. A touch more risky, but not much.
Do a search on otter box here and you will find many reports of them leaking. I think heavy duty (think can light canister without the battery) is going to be your best bet if you simply must bring largish object down to depth and keep them bone dry. A cheaper solution may actually be flashlight without without the batteries! But any case, even a good quality one, can leak if you're not excruciatingly careful: witness the horror stories of flooded cameras in expensive cases that are DEFININTELY designed to go to depth.
