I don't, I only just have a sub. What are you looking for advice/ideas? I have no advice but lots of ideas! I only have a problem with Lack of funds to turn it into reality!
I really don't think there's such a thing as a practical boot once you put a Sub in there!
I had to get the Jack out the other day and it was an effort as I had to lift the box up to get under it to lift the boot floor up. My Jack wasn't even there I had changed my sisters tyre and left it in her boot..
I would be too scared to use my boot anyway if I had some nice gear in there. I always worry that in gonna open the boot and something has slammed through the sub. I don't really have a pic of my sub.. I do but it was taken to show a flag on the boot so you cant really see the sub.. might take one tomorrow.