This might be of interest to those wanting to mount their phone or GPS device to their GoKart. We bought one and it’s been in use for a few months. It has a nice sturdy construction and can be easily and securely attached near the top of the trolley.
https://www.gear4music.com/Recording-and-Computers/KandM-19761-Smartphone-Holder-with-Clamp/68MN?