For a simple "thigh" mount for any of the 4.3" satnavs (& this includes the SkyDemon or Aware unit), try:
Price is certainly reasonable?
Simply put a suitable length of elastic strap with velcro ends, through the belt loop on the back & wear it "On the thigh". Maybe have an old unused Kneepad?
Works a treat even in the RVs.
Regards,
Max