Mine is simply laying on the floor of my 80's cargo area under my dog platform. In an accident it can't really go anywhere. The platform is bolted down. So it might make a thump on its bottom side at most. Hate it there but have not made the time to redesign a tire carrier on my swing out with a mount for the jack yet. But it will be on the swing arm by CM13.
I tried the front bumper mount but did not like it blocking view and access to the engine compartment. Roof rack seems like a accident waiting to happen during access to it. No where is perfect but I like the swing arm the best. If I'm pinned and I can't get to the jack then I can't get to the tire and its all a moot point.