I been looking around for the tablet holder for my BMW 650i and finally I found this simple bracket but it dose exacly what I want and it make inside my car look like the cop car and it the tablet solid.
I am using this for the Lenovo Yoga 12.5 screen .

Great choice over the windshield mount.does not block your dashboard or stereo and is very space saving.very easy to install.pleased with it

Pros: Plenty of mounting options even for an unusual application such as mine (mounting on a wheelchair rather than a motor vehicle).
Decent tablet mount variations.
Cons: Plastic flex surrounds a bendable metal interior, rather than a spiral metal gooseneck. Expect to thus have a very finite lifespan.
Worried the plastic flex interface is a weakpoint.

Mounted it in my truck, I need to go on a trip and my car wouldn't handle the drive, so I took my old truck. I mounted this on the passenger side seat bolt and then, followed the instructions, used it to old a Samsung Galaxy 10.4 tablet. It held the tablet along with the leather case without any trouble. I positioned it so I could see it, and used it as my SiriusXM radio, the Google maps as my GPS. By mounting the tablet, ti brought my old truck up-to-date with the technology that makes driving better and easer today. The base worked great, held the device, allowed me to drive and used the tablet without fumbling around. It's an excellent product.

I coupled this with an iPad locking case Kensington SecureBack Security Case and Lock For iPad 4 with Retina Display, iPad 3 and iPad 2 (K67751AM) and couldn't be happier. My BMW didn't have the iDrive system, so I figured an old iPad 3 would make a good permanent fixture. After finding my passenger seat difficult to loosen the bolt, I ended up screwing this thing directly into the center console (not recommended without knowing what's under there). I lucked out and it's held tight. My ONLY complaint would be that it shakes slightly while driving but you have to understand there is a lot of weight on there. If it WEREN'T flexible, I suppose it wouldn't shake, but that's one of the best parts about this. I can easily adjust the position to move it away from a passenger's legs, or move it away from the shifter. It's also awesome how quickly I can rotate the screen to landscape and back to portrait mode.

Pros:
Great build quality
Multiple mounting options
Holds iPad perfectly!

Cons:
Really none. If you want to fault physics, I'd complain about the slight shaking of the device, but again, that's not the fault of this product.