I believe the QP spares are easier to come by then on a 4200. For me, I need to be self sufficient. When I was looking it the spare tire kit it was impossible to find so I went with an alternative that was proposed on the UK forum. It consists of a spare from and SL Benz and a custom adapter. I currently have this set up for sale on the marketplace here because amazingly enough, I found and bought an OEM one not to far from where I live. @Piloto, a quick ebay search resulted in a few kits for QP's.