Perhaps this is one of the products I buy in China: car holders for tablets. This is one of them, adjustable since 7 until 10 inches.
Has two parts, a being trapped in the car and another to fit the tablet.
The bracket will be mounted so:
This is one of the best holders I've ever seen in regard to the quality. But stay tuned to upper buttons, as they may be prevented by supporting.
Very good support, but it turned out to be not very useful to me because my car GPS has a power button on the top! I leave the link to your product below. Also, look for tablet and cell phone holders for cars in all Chinese sites using the search AllChinese the TudoVemdaChina.