I need 2 wheels for rear of my mustang gt to mount snow tires on.?

i just moved to upstate ny from s.c. i want to mount 2 studded snow tires on the rear only just to move the car around in my parking lot the car has 17 inch rubber on it now i am loohing to put ANY 15 INCH SNOWS ON AND DO IT CHEAPLY i was thinking from a junk yard. thanks merry xmas.