exactly how I started Chris
TBH recording footage is pretty easy, turning it into something watchable is more like witchcraft imho.
Things I've learnt
The battery life is shocking I have 2 spare batteries, alternatively look at a skeleton housing and running a power line to the GP from a 12v socket or usb. Downside of the skeleton housing is you lose the water and dust proofing but gain better sound. Buy a 12v charger for the trip
TBH sound recorded off road is pretty dull, lots of bangs rattles and me talking to myself
much better to edit it with some nice tunes
Variety is the spice of life! one camera angle will produce pretty dull footage, you need to move the camer for lots of interesting view points, multiple vehicles mean this is easy and one truck can film another. Suction mount is great for changing angles quickly but I always back mine up with a tether when mounted externally in case the suction fails (it hasn't yet)
Footage of near vertical descents look like minor slopes on film
Vibration is a killer on footage, make sure mounts are very tight to minimise this
Timelapse footage is great fun, I have a cheap £20 panning mount which process great film
The app is a great tool, I leave the camera set up and then use the app to film lots of short clips over a day instead of 1 long section. This helps make the most of the battery life but I still delete 80% of the footage
Storage - filming in 1080p (full hd) eats up your memory cards. I take a laptop with me for various use and backing up video, last year I shot over 400GB of footage. This year I'll also take a 2TB usb hard drive so I can collate everyones footage.
With the trip, a few of us have cameras and Georges friend is a film maker so between us we'll get some great footage and should be able to compile a decent film of the trip