And she's mounted. Used some Aluminum Angle up top to hold it up and in place. It stayed up and in place real well with just those 2 brackets, but since it's thinner metal up there it could swing a little bit if you pushed on it.
So... dug in the trash can where I've been putting everything I've ripped out of the car. Found some left over steel strapping from the ghetto bass system the original owner had installed, which I ripped out. Dug in my can of misc bolts and found 2 small matching bolts that threaded right into the chassis. Can't say I'm a huge fan of using this strapping stuff as it isn't the cleanest looking way to mount stuff, but all I needed was something to prevent swaying and it really worked perfect in this case. Pretty happy with how it turned out in the end.
Threaded Mode