G'day fg I use the ram mount mounted on the seat support and a couple of small chains to stop if vibrating also they un clip so I can lift the seat up to access the motor there's a photo of mu cab on my profile album cheers Daz
Ram post. You can change height to what you want and bring it closer or further away. I use it to mount my Surface Pro3 but there are a lot of different holders to suit what ever you want. It is bolted to the floor and as you can see it has a stainless plate to help stabilize it that is bolted to the top just before the engine cover. Engine cover can still be opened but I tend to just tilt the cab. Over corrugations any mount will be a problem with movement but this is the best I have found. It is mounted in a position that three can still sit in the front but why would you as the centre seat is really not meant to be used.