A basic button box I created to work with arcade buttons. I used large arcade buttons since I use a VR headset. This connects to the front mount of the simagic alpha servo bases. For my build I used large arcade buttons, since I drive with a VR headset, and a common usb arcade controller from Amazon. The side of the box closest to the servo base makes contact to give rigidity when pressing buttons. I do not notice any movement when pressing the buttons while driving. 

I used 3mm threaded brass inserts inserted into the box for attaching the front panel and maintaining strength.