US Android 4.4 Quad-Core GA5180F 7"Car DVD Player GPS l for Chevrolet GMC Impala

I have a new android head unit installed in my 2008 Chevrolet Tahoe and wanted to root this device so I could partition more space for apps from the 16GB nand flash. If somebody could point me towards update.img or any help would be greatly appreciated. Specs are as follows:

Model number: S07
MCU Version: MTCB-KLD2-V2.51
Apr 22 2015 16:19:18
Android Version: 4.4.4_15052015
Kernel version: 3.0.36+
root@ubuntu #13
Thu May 13 22:17:41 CST 2015
Build number: rk3188-eng4.4.4 15052015 09:27:36
CPU: armv7 1.6Ghz (x4)
Memory: 1024