If you are willing to drill a hole in the mirror and trail the wire that way thru, you might stand a chance with a MC camera.
After all you should be able to screw the camera onto the mirror pretty good, and if you route the wire thru the mirror what wire you have between that and the camera unit will be little.
But yes the wires are pretty thick around 6-7 mm i think, at least the wires on my dual remote dashcam are that thick, easy to tell from a ordinary USB wire on the computer.
The camera units on the Gnet camera should be waterproof, and as it sit there close to the door / front panel gap i think it should also be protected by the mirror i assume will be sitting almost directly above it.
But yes would be sad if the camera housings was made in really thin fragile plastic, also i am not that happy about the chrome, but as a painter ( too ) i will have no problem painting the camera housing the same color as the car using a can of repair spray or regular repair paint i can transfer to a airbrush.
I was in Singapore in 1990, the taxi driver from the hotel to the airport,,,,
only time i have been afraid in a car.
Otherwise very nice place and traffic, i hope to visit again some day soon before i get too old to travel the world.