I think that ATM most dashcams still top out at 128GB memory card size, some do officially support 256GB and very few are tested and will support 512 GB
Now if you are driving across the states, and do so fast, meaning several drivers taking shifts, and still we are not talking cannonball run, then it will probably take more time than a single 512 GB card can provide.
So the best solution is to pull over now and then, which i assume you are going to do anyway, cuz i have tried to drive far ( +1000 km ) in one go and that is just not cool with no stops.
So you can use stops to offload footage to a larger means of storage like a laptop harddrive.
In regard to the concept itself, a dashcam do record video, but the people that make scenic drive videos, i am sure none of them use a dashcam for that as really aside for it being video it is something else.
A proper nice drive video, you do not have dashboard or A pillars in the frame, and you would record on a higher bitrate camera as you will want the best possible detail amount, and a dashcam record in a very moderate bitrate VS a proper video camera that have 4 X higher bitrate,,,,, and as a consequence of that also generate about 4X larger files.
A dashcam is a compromise camera, it use a lesser bitrate and so image quality in order to generate as small as possible files and put as much as possible video on a memory card.
So it is a compromise getting just enough detail to provide useful evidence in case of a alteration, and memory space.
A 1080p dashcam will generate about 350 MB files every 3 minute ( from each camera ) if you record sweet 4K using a good action camera you will probably see around 3000 MB for every 3 minutes you film.
Memory card life time are set in full write cycles, so while in theory you could make do with a 32 GB card and the few hours it hold, then as it is a smaller card it will also burn thru write cycles faster than a larger memory card, so for this reason a larger memory card is also preferred.
If the memory lasted forever, well then you could make do with just a 8GB card which would just store the last 30 minutes of driving, BUT ! then you do not have room for locked event files for instance as those the camera can not overwrite so creating those manual or automatic and you just end up with 0 memory for the regular driving video.
Most cameras today have a set amount of memory space reserved for events, and once that fill up they will also get overwritten with the oldest ones deleting first, yet another reason to have a big memory card as that will leave more room for such files, and providing you do not generate too many the retention time of these will be going back months with a large memory card.
My cameras can only generate event files if i press the event button, or if my car while parked get hit hard enough for the G- sensor to trigger.
You
do not want to use G - sensor while driving, it will create too many false events from potholes and in other way poor road surfaces, and you
do not want to use motion detect while parked, cuz every micro movement of something will set off one of those.
If you want to see how a scenic drive video should look like, look up the youtube channel called American roads.
https://www.youtube.com/c/AmericanRoads
Today the bare minimum for a single channel in a dashcam should be 128GB so 256GB if it is a dual channel system, you can make do with 64GB for each camera, but then you should be financially challenged as opposed to it being a deliberate decision.
You can also make do with just a front camera, CUZ it record what you do with your vehicle, and if you do nothing wrong, then surely what happen off camera can not be your fault.
I have used dashcams for about a decade now, and +95 % of things i want to share have been captured on the front camera.
BUT ! you should still get a 2 channel system ( front & rear ) if that is possible.
Some cheap systems still, well they dont recommend more than 64GB memory cards, so you should not just go large, you need to make sure your hardware will play ball with that size.
Doh!! I didn't read your post that way. Sorry about 'haranguing' you about what you currently had.
