Avoid the roof lining. Having had the roof lining down on my old B8 A4, I know my way around. The interior as Matt mentions is easily marked. You need a special tool for the interior grab handles, assuming you don’t break the clips or they ping off. If you do go down this route, disconnect battery at least 30 mins before attempting. There’s airbags behind A pillar and curtain airbags. The B Pillar trim is straight forward, but it’s things like rubber door seals.