For the Curt hitch part # C11438 that you have installed on your 2005 Volvo V50i has a recommended ball mount, part # C45522. This is a couple inches longer than the # C45561 you currently have so it would give you the clearance you'd need.
For a 2 inch hitch ball you'd want the part # C40018 or for a 1-7/8 inch ball part # C40001. view full answer...