Piling onto myself here;
Car VAO is entirely fine and dandy if the car is already built on a solid base, and now with the bakery x4's using that has bounced light there's no issue with over-darkening of interiors, but with the current public release of the OptiX Bakery (v8) which is the one used for baking cars there was no bounced light and as such many interiors ended up far too dark for actual human use. I only recently caved into it by baking at 50% ambient occlusion opacity meaning only very light shadows were added to supplement my PBR configs, but for cars that aren't pipeline standard the bakery will spit them out in horrible condition.
This is what happened when I tried to bake VAO for the first time on Some1's C6, the door was parented to the COCKPIT_HR node rather than being under a body dummy or having no parent at all, meaning the bakery considered it part of the interior and tried to brighten it up. Most "bad mods" you'll find won't have a COCKPIT_HR node and as such the bakery won't actively be brightening the interior up, it'll all just be baked as if it were the exterior in a rough and dumb manner.