Hi Riggers
My solution was to make a custom centre mount and use Ram Mounts with the 1" ball. Not the cheapest of options but practical. Uses a normal car Sat Nav and you can still see the speedo and warning lights.
Left to right: Custom centre mount with Ram Mount RAM-B-238U Diamond Ball Base with 1" Ball 2.43" x 1.31" £8: Motorcycle Ram Mount Extension Arm for 1 Inch Ball Black £18: 5" SUNSHADE GPS SATNAV CASE MOTORCYCLE MOTORBIKE 1" RAM BALL WATERPROOF 5 INCH £29
5" SUNSHADE GPS SATNAV CASE MOTORCYCLE MOTORBIKE 1" RAM BALL WATERPROOF 5 INCH £29
Custom centre mount with Ram Mount RAM-B-238U Diamond Ball Base with 1" Ball 2.43" x 1.31" £8
Jolly Bodger