It fits perfectly in the trunk above the floorboard. There is an indentation that it sits down inside of, snug, and doesn't move around. Yes, you will have to live with less cargo space.
I'm going to have a cover made for mine. One thing I forgot to mention is that you need five two-inch long wheel bolts to work with the spare because the stock ones are too long. You can get them at your local tire/rim shop. It's really nice to finally have spare, and everybody talks about what are you going to do with tire you take off when you get the flat, but that will sit back in there too (in the indentation in the cargo space).