If possible, I'd use two flash drives, mirrored with soft-raid, for storage. One clearly visible in the dashcam, the other hidden somewhere deeeep inside the car with an USB extender.
Why? Because if a cop/other driver ever gets mad at you and forces you to hand over the flash drive, you still have a copy.
Also, I'd add two microphones to the project, one for exterior sound, one for interior (e.g. to prove what exactly has been said, or in case of a crash if other drivers have honked, or if an ambulance had its sirens on).
And, I wouldn't use a Pi, but rather something supporting SATA, because USB flash drives tend to have low lifecycles when constantly overwritten.
Why? Because if a cop/other driver ever gets mad at you and forces you to hand over the flash drive, you still have a copy.
Also, I'd add two microphones to the project, one for exterior sound, one for interior (e.g. to prove what exactly has been said, or in case of a crash if other drivers have honked, or if an ambulance had its sirens on).
And, I wouldn't use a Pi, but rather something supporting SATA, because USB flash drives tend to have low lifecycles when constantly overwritten.