It’s a collision issue - like wheels are penetrating suspension and chassis, you need to add custom collision channels, check my previous post. I might append them with a prefix in MMT_Content to avoid name clash if you already have custom channels.
Controls for camera are set in MMT_Controller(PlayerController) as far as I remember, I’m using the simplest “orbit camera” setup where controller rotation is used for pawn’s camera. Controller class should be in root folder of “Blueprints”.