Ski rack for a convertible mustang?
 

Does anyone know of any ski racks that don't require a hitch or a roof for mounting? I want to take my stang up to tahoe and am just now thinking about how to fit 2 snowboards and 2 pairs of skis in the car with us. I've seen miatas with ski racks on the luggage carriers. Does anyone know of anything like this for a mustang?
Thanks for your time
Dan