Can't change MAC address on Rooted Android Nextbook Ares 8
There's a file called mac.txt in /config/wifi, which contains the MAC address, which is the only thing in the file.

Changing this value, and then enabling the wifi adapter results in a new MAC address.  (Confirmed by logging into a router it connected to.) This change survives a reboot.  

Now to research how to write a script to randomly pick a manufacturer prefix number and the rest of the digits at every restart, along with setting a temporary randomized hostname (setprop net.hostname xxxxxx).

I found the MAC text file by searching the device for files with Total Commander.