google image search "trunk luggage rack" see if you can pic a make/model car that has a similar shape or style trunk with a luggage rack on it. then try to see if you can find a wrecked one part out, or borrow one to get measurments and order one, or go to a rack shop to see if they have anything to play with.
theres not one made for our cars, and therefore I highly doubt anything will be a direct bolt on. but if you get one to play with you could modify the mounting points and make it work. i'm not sure if I would trust our trunks to hold that much weight as the trunk and fenders are pretty soft. I would just go with roof rack if you want to carry things.