I'm not an expert, but to me it seems to be caused from how they implemented UE4's autoexposure/eye adaptation.
You can see this effect in action when switching from an exterior bonnet view to the dashcam / cockpit - once behind the glass the road ahead is briefly dimmer and how it probably should look, but then quickly ramps up to being overly bright.
Disabling the auto-exposure in the engine.ini on PC straight up breaks everything, though. All you get a bright white screen if you disable that setting, even in the garage / menu scenes.
It's mainly an effect that makes sense in third / first person games (which Unreal is primarily designed for). Like when you're inside a darkened building and your "eyes" have adapted to the darker setting, then you look outside a window or door and it seems way brighter and blown out out there, and when you approach traverse the door its even brighter but then calms down once you're actually out in the light and your eyes have a adapted again, but this time to the sunlight. The problem is, the inside of a car should not be doing this sort of thing at all with all the windows letting light in, it's not like a darkened interior of a building, but it's still acting like one with how things are being rendered with the current autoexposure & eye adaptation settings they having going on.
They really should remove this effect entirely. It's absolutely pointless for a game like this. The only thing that maybe... maybe should have anything like this, is a long dark tunnel on a stage itself. Not the car interiors. Definitely not the cars!