in the past, it was a little fan boy, but on previous vehicles I placed light bars just under the dash and under the seats.
Initially I had them plugged into the cig lighter but later I hardwired them into a constant 12V with a switch. I would jsut it as a flare piece on dates but it made a decent lighting for night.
The best thing to do would be to hook it into the same wiring as the dome light. a constant 12V power that would activate when you open the doors. It might take a bit of wiring thou.
Maybe a project when the weather gets a little warmer.