MORE THAN JUST PRETTY ARMOUR
I've lost count how many Rhino transports I have built and painted over the years, but in all that time I have never not painted the interior. I appreciate that may seem a bit strange to some hobbyists given most of the time you will never really see the interior and I know for a fact a lot glue the back door shut anyway. It started in part "just because I can", but now I do it because it really helps place the model into the world for me and gives it that extra element of visual interest for the viewer. Not all kits have an interior but those that do I go out of my way to paint fully, seat covers and consoles included.
ONE METHOD FOR THEM ALL
Regardless of the legion or the vehicle I use the same basic method on all of them. Primed black with a rough zenithal dusting of white to give a basic greyscale, followed by either a deck tan or neutral grey colour application using the airbrush. Which I go with depends on the legions primary armour colour and whether I want a warmer interior or a neutral/cold. Whichever I go with I then apply a contrasting sponge chipping, metallic texture and paint the basic details such as storage bins, consoles and trunking. To tie all together and give the interior some tonality a generous coat of varnish + wash goes over the top. The kit is then assembled ready for exterior priming.