Depends exactly what you're looking to change. If it's the cloth panel on the door, it's usually re-wrapped with cloth, vinyl, or leather.
I had the plastic on the door panel painted in my last 8G and it was a pain in the ass. Scratched easily and was hard to touch up.
The arm rests / radio / shift bezels and vents are easy to paint and can be durable if you prep them well. Usually a 800 grit sand to get the clear coat off and smooth it down if there are no cracks.
You can also vinyl wrap your plastic pieces.
Here's my old door panels:
New 8G: vinyl wrapped the panel, carbon vinyl wrapped the arm rests, painted behind the door handle:
before i painted the cup behind the handle
after:
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