Head Unit Storage Problem

[Wulbo]

Hi I have a Pumpkin 7 installed but I have a few problems. It has 32gb of storage but I can't update or install any apps on it as it comes up saying storage full please make more room, but when i go to storage management it say's 8gb of 32gb 25% used. Another issue is the guy that installed it said he couldn't get the steering wheel controls to work with it. I had a look on youtube and it looks like I need some PCB to assign the steering wheel controls, does anyone know whee i can buy one of these?. Help appreciated, thanks!