BlackVue DR750S 128GB 2-Channel Dash Camera

I don't have this exact model, but an older 2-channel version. Some quick thoughts from me: If your cigarette lighter is only outputting 5.7v, you have an issue in your car's wiring. It should be 12v, this is why the PMP isnt working probably. The Blackvue SD cards are more expensive but there is a reason for it. These cards are designed for constant heavy duty read/write. I also had the same thoughts as you and ended up getting a cheaper Sandisk 256GB card, but that got corrupt after a few days. Comparable SD cards would be Sandisk's "High Endurance" line designed for surveillance. Those are cheaper than Blackvue SD cards but more than your standard SD cards, I've been using one for over a year now.

Quick its $1 off!