Car holder for Samsung Galaxy S7, and HTC Desire 620

Holders are designed to be joined together with 6mm aluminium rods. Rods should be attached to you obsolete navigation holder with screws or zipties.
Galaxy S7 with back cover has the same thickness as HTC without cover, so both slide nicely.
Left side exposes light sensors, otherwise phone would switch to minimum brightness (when automatic brightness mode is enabled). There is also cutout for speaker.
Righ side exposes S7 home button, microphone, another speaker, and micro USB connector for charging.
I printed both sides without supports - they are designed for efficient bridging with vertical walls and continuous top cover between them.
Be careful when attaching right side to rods. I immediately broke upper part. This may be considered feature since now back button of S7 is also exposed, and wall is needed to print right edge :)