Why would you want a dash cam on if the ignition is off?
I bought a couple at Lazada and they are okay. But you need to fit them yourself or get someone to fit them which costs extra money.
I went to my local Honda dealer for a service last week, and they were selling two different versions for around 2,300 baht each.
It looks fine. And of course they fitted it for free
It's one of these small digital mirrors that hangs underneath the main mirror with the camera pointing forwards, and wired through the car to a camera stuck on the back. I previously bought a cigarette lighter extension lead so that I have three cigarette ports which I put in the glove compartment. So I still have power from that despite plugging the mirror into one of them.
For your information I previously bought one of these wide 10-inch mirrors to strap over my existing mirror. I liked it for a time, but the shiny reflective surface of the display can be difficult to read when you glance up from driving the car. So after using it for over a year I have gone back to using my proper mirror and having this small mirror hanging below it.
Using the proper mirror of course it also means you can talk to your friends sitting on the back seat which you can't see if you're using a full camera!