It's a year later but randomly ended up with both of these. Haven't used the GPS device yet as I've been using the phone GPS which is terrible btw.
Also got this to put the GPS receiver against the windshield. Going to get some velcro tape for easy removal of actual gps Device.
https://www.sportys.com/windshield-suction-mount-for-bluetooth-gps-receivers.html
Have been using Track Addict on my Samsung mounted to the Tackform and Race Render for processing. Track Addict is great. Race Render is clunky and not intuitive to use, but I've gotten used to it now.
At this point, i don't think i need standalone camera or anything.
Only other thing might be a headrest mount to capture steering.
Here's an example.
I then updated gauges so they're larger