Suzuki uses this squeeze method for attaching ground wire to the bulb socket. If you use my method of making the auto-parts store sockets fatter, make sure you position the metal sleeve so the bare ground wire touches the sleeve.
You could always go to your Suzuki store and buy a new set of Burgman rear sockets to put up front, but you will pay $25.00 each. I know, I checked. Mine cost $4 each.