Question about interior detailing

Depends on the kit.  Some kits DO have interior upholstery panels, but none I know of have the ceiling upholstery.  Usually most folks paint that area an upholstery color.  What to do about window areas inside depends a lot on the builder. Indeed some just paint that body color (used to be full size cars were that way too).  Race cars are something else, usually  no upholstery, just like full-size race cars, but interior paint depends on racing team- needs to be determined by research.

Thank you for your detailed response, that helps.

Actually the new Revell 68 VW Beetle has a complete headliner, a seperate part, I know there are one or two others, and I have seen some with molded in headliner detail. Some kits have c- pillar detail as well. If not detail is present, I just use whatever interior color I am  using, and brush paint it.