I have done mine like this, just to add on to what Ozzy was saying I knocked up this drawing to explain it on another forum.OzzyQashqai wrote:Nice write up!
Excellent point raised about installing a "tap-a-fuse". Ensure that the "tail" of the tap-a-fuse is away from the "hot" side of the circuit. Failure to do so defeats the purpose of the fuse!
In my case, I bought an auxiliary cigarette socket (with USB) from an electronics store, secured it into the dash cavity with double sided tape and wired into the fuse box with a tap-a-fuse. Into this went the dash cam supplied cigarette power supply.
The 12v feed could also be at the bottom so it needs to be checked with a multi-meter so you know which is which.