I used this post from another TMC member named Arek Iskra his Blog EvCharged and found it very helpful.
BlackVue DR750S-2CH installation in 2017 Tesla Model S
This TMC thread was also helpful for power.
Newer VIN constant 12v power options (dashcam)?
I mounted two BlackVue DR 750S-2CH like you want to do. I put the main larger camera of each pair facing front & rear with the smaller cameras in the rear triangle windows on each side with a small wedge, purchased from Home Depot, then cut to the size of the mounting base of the camera. You will need to turn on the camera and figure out how much angle in needed to reach the front of the car and overlap the front & rear cameras scanning area. It helps to have window tinting to hide the side and rear cameras. I ran shielded wire (aircraft wire purchased from Skycraft Parts in Winter Park, FL) with the coax to the rear large main camera to supply the power. Make sure to put a fuse for each of the paired cameras power. Get the Polarizing filters made for the front and rear cameras, it helps. The 360 degree setup with 4 cameras is so helpful recording while driving and when the car is parked.
If you have not purchased the BlackVue cameras yet checkout.
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