In most cases dual lens dash cams are a bit too expensive to be worthwhile because they do not offer the same video quality as single channel dash cams. They usually:
- Have lower video quality (resolution or bitrate) than 2x single cams that are the same price or less expensive
- Have lower reliability because more data is being written to a single micro SD card
- Have a lower quality image sensor for the back cams.
The benefit to dual lens cameras is their ease of use to set up compared to 2x single cams. Everything is done in a single body, including wiring, memory cards and wi-fi connections.
Dual lens dash cams will usually not be the best choice for the money until a camera with a reasonable price point and high resolution becomes available. It is cheaper to install two standard cameras instead and the result is far better video quality. There are several 1080p and 1440p cameras available for less than $100 per piece that will have significantly better video. If you’re buying a dual lens dash cam buy it for the other features it offers, not just because it has two cameras built into one.