Your RAV4 should be an ideal candidate for a hitch-mount rack. Go to the Yakima website and you can enter your car information and it will tell you which racks will fit. A decent hitch rack will fold down so you can still open the rear hatch without removing the rack.
IMHO, hitch racks are far superior to roof racks, and I have used both. Roof racks create a lot of wind noise, reduce gas mileage -- plus you can hit things like garage doors. Hitch racks don't make any noise, have less effect on gas mileage and don't stick up where they can hit things (although someone could always rear end you and damage your bikes that way).