Very practical. The first few pictures look like it's infinite baffle, which would work as long as the entire trunk is sealed off well from the cabin. The third picture looks like the woofer is enclosed in a smaller box, which would work too. Yeah, the first setup uses the whole trunk as a box, as the last picture is sealed off i believe. I think the last picture is what i would want though. Will it still sound great like that or will there not be enough space? Thanks