wiring dash cams

(Sorry if this isn't the right forum, I wasn't sure which one to post in for this topic) Hi everyone, I'd like to put two dash cams in my car (front and rear). There are so many bad drivers on the roads I think it would be a decent investment just incase something happens. I want to be sure of the wiring before I order anything and am hoping you can point me in the right direction. This is slightly more complicated than a normal dash cam install that turns on with the ignition, because I'd let to set it up in the following way: 1. If the ignition is on, the cameras are on 2. If the ignition is off, and I flick a switch, the cameras turn on (so if I'm parked for a short time I can leave them on) Hopefully you're thinking that's easy... I've drawn a sketch of how I think it might be laid out. If it's completely wrong please feel free to say! The cameras run off 5v so I think they need keep the cigarette lighter transformers. The main thing I'm not sure about is the two + wires (at the bottom of the sketch). What I need for these two wires is one of the following: 1. One fuse which is always on, even when the ignition is off. One other fuse which turns on when the ignition turns on. I'd use a fuse tap on both fuses, like below. 2. The ignition wire and 12v wire going into my stereo. Can I splice into these? Can the ignition wire power the cameras? 3. Is there another "ignition on wire" and "always live wire" behind the dash that I can use? Here's my sketch...hopefully you won't laugh! Thanks in advance

Your circuit is ok as long as you have your power sources. We don't know what year, make, and model car you have to tell you where to get your 12volt sources. However, if you have a CIG lighter port, that's always HOT, you uswe that as your hot. Then an ignition switched source. I have a Charger. The Port in the center console is always hot, but the port on the dash is ignition hot. My radio wires are ALWAYS hot, it's CAN BUS Controlled. YOU have to test your wires with a volt meter or test light to see what's hot and when.