There are a number of rear 2 inch hitch carriers- This one is my favorite:
pros- it rocks and can make the car VERY comically capable:
cons- really need to relocate license plate and lights/also- cannot open rear hatch with carrier in place.
I am a huge fan of roof racks- heres another pic- the volvo xc70 can hold 2 (two) racks at the same time front to back:
If you are travelling, I highly recommend the roof racks for versatility.
Good luck,
Ron