Need to dim ALL of that past dusk as it significantly interferes with night vision for any distance.
One radio is adequate at any time, otherwise, given need day or night for greatest visual distance without interference to concentration.
There are some decent examples of how to mount. I’d start with passenger seat floor bolt laptop stand and adapt from there.
One radio is not adequate for what I do professionally. You can't effectively monitor dispatch and TAC channels on a single radio. You cannot effectively monitor incoming mutual aid while monitoring dispatch and TAC channels. While three radios are scanner, other radios are separate because some of what I have to monitor is VHF, some is UHF, some is 7/800. Often when there is a call operating, scanners are all locked into one channel and only one channel, rather than scanning. This way I can monitor, for example, dispatch, TAC/Fireground, mutual aid, law enforcement, water supply, and then if one scans, it is scanning towns immediately surrounding us, to monitor other incidents that may be requiring the same resources we are utilizing. For a water call, a radio monitors Marine / Coast Guard, for calls on the interstate one radio monitors the state police while another monitors town police.
I have no laptop set up in my truck, however I do use a tablet, which you can see and it is mounted effectively, so I am not sure what you're getting at here. Why do you think i need a laptop? I had one but found that I can access CAD, EOC portals and weather from my tablet, which is much easier and more effective.