MY EXPERIENCE
The car-mount works perfectly with mirrorless cameras like the Sony A7SII and Panasonic GH5. I've had no problems bringing my car up to 60 miles per hour with this camera mounted on the hood. The mount will work if secured properly on a clean and flat surface. Mounts are all -1/4"-20.

PRODUCT DESCRIPTION
The Delkin Devices Fat Gecko Triple Mount is designed to hold DSLRs and camcorders up to 12 lb. The mount combines a Fat Gecko Original with a Fat Gecko Mini mount, and a slide and lock design ensures secure attachment between the two mounts. By combining the two into one mount, Delkin has created a sturdy mount that affords three industrial locking suction cups for increased stability. Plus, the suction cups can adjust to the contours of your smooth, non-porous shooting surface. The mount locks into place and features six adjustable points, which ensures you'll get the mount set to the perfect angle for every shot. The mount also features a standard 1/4"-20 tripod head for universal compatibility. A rubber washer and tightening knob provide added vibration dampening as well.

* Attaches to smooth, non-porous surfaces
* Equipped with three suction cups for increased stability
* Supports 360° tilt, turn and rotation
* Maximum height from mounting surface is 8.5"
* Minimum height from mounting surface is 3"
* Features a standard 1/4"-20 tripod head
* Rated for DSLRs and camcorders up to 12 lb