Front: you can put it on the dot matrix area next to the mirror housing, with the camera lens peeking below

Rear... probably low on the rear window, with it adhered to the trim on the hatch

 

Are we talking TWO cameras, one forward view, one rear or we talking those goofy ones that have two cameras built into single unit and all they do is to show rear seats?

 

lol. goofy ones

 

I put a Fitcam on my Grand Highlander. Easy to install and looks OEM. No GPS or speed info though. If you do go this route, make sure you specify that you have the digital mirror. They had to ship me a special piece.

 

You can take a look at this thread of a unit I installed in my Highlander. It's slightly different in that it's a head unit with camera and a separate rear camera. Independent of the one from the factory. Has photos.
(3) Just wondering....Anyone tried one of these? | Toyota Nation Forum

 

Towards the center as much as possible and high up. I have it on the passenger side and another unit in the rear at the highest point.

I personally prefer to have high resolution (at least 2K) on both front and rear, so I have two separate cameras. I avoid the dual (or triple for that matter) as the HD quality is horrible at night with most dash cams. That or they fail over time due to heating issues, which isn't uncommon with dash cams.

Viofo A129 has been my longest go-to. Longest lasting and they simply work.

 

Lots of ideas, discussion and pictures going back over 10 years in this thread at DashCamTalk - Where did you mount the camera? Post your pictures | DashCamTalk

I mounted the camera in my Venza on the sensor mount similar to the 2nd post in this thread ( Best place to put cam? | DashCamTalk ) and the rear camera just off center on the rear hatch.