Yes it's CARBON not Plastic. For weight reducing.
Quote Originally Posted by View Post
We tinted our 500L about a week ago and had the same issue. The rear side windows are plastic and should not be tinted.

We went with Light tint all around and did not tint the back plastic windows. Since the rear windows are already tinted the light was enough to give the car a much darker look and the back windows still look darker due to all the other windows that we tinted.

You may also think about tinting the sunroofs if you have them. We went dark on the sunroof and it made a huge difference on the interior heat. You can still see out, but the inside temps went down by a lot.

Hope that helps a bit...