Its very different in that on planes it's literally built to survive basically anything and is critical. In vehicles obviously it's not even close to the same standard, and I'm pretty sure it can get corrupted in a collision. But they're supposed to automatically save a 30 seconds pre-impact of speed, throttle/brake position, and seatbelt status. Though, I'd guess It's also very manufacturer dependent how good that data recording will be for anything more or better than that, but they should all have those basics.
I just know for Teslas the amount of data that gets saved would probably shock most people because in addition to the EDR it is the most software advanced manufacturer and also records everything with its autopilot system (so like 7 surround video and all the data you could imagine about the vehicle status down to how rolled down the windows are and ****... that auto saves when it detects crash or even setting to autosave when you honk and ****) which is stored separately
This as an example.
Also I'm sure some manufactures make it a headache to extract the data. Some make it easier than others and you can do it straight through the can bus or better...