I will say it’s quite a bit more expensive than a typical off-the-shelf consumer dash-cam, since you’re essentially just installing a full-blowm compurer. I use a Raspberry Pi 5 for the pre-made kits, which is able to record 30fps@720p across two channels (front/rear). It’ll work with just about any USB webcam. The tricky part for new users is that you typically have to create a 12V to 5V USB harness to power it from the car.

This is a bit of self promotion, but I built an entirely open-source dash-cam that excels in this scenario. Instead of recording to an SD card inside the camera, the camera is connected to a capture device installed somewhere else in the car.

It’s not perfect, but it’s very time consuming for a potential adversary to locate the video storage. It was designed like this primarily for car break-ins, but it would work well here as well.