Caravanistan

Here you can read the guide on the public service website of Zhejiang province for reference. (But they forgot to delete the requirement for health check and "traffic law education")
There's very few information about the situation in Xinjiang, but the application procedure should be the same, unless the police officers are too conservative ("No such requests have been processed before") or there are "special policies" issued in Xinjiang.
More updates will be posted if there is a new situation.
http://www.zjzwfw.gov.cn/zjservice/item ... 748ab14c75

The original text of regulation law for temporary entry vehicles and drivers (Order No.90 of MPS, Dec 1, 2006) is here:
http://www.gov.cn/gongbao/content/2007/ ... 772748.htm