Thanks for your replies ,It's not so much the mount ,I've got a ball mount from ultimate addons on my rc8 with a dedicated 1020 holder,just about to get a 1190 adventure with a garmin holder (I think) already on it (hopefully there will be a garmin to three prong adaptor available) .Just concerned that these universal holders won't hold a 950xl securely,waterproofing shouldn't be too much of an issue as the holder is above the clocks behind the screen,will have a look at the universal Spring loaded cell phone holder