I didn't like the default AMS damage car icon on the bottom right of the GUID (As shown above) - so I modified the one I used for Game Stock Car.
Please note that it is a Formula 1 car, so if you don't play Open Wheel classes you might not like it. Please make a backup of your Automobilista\GameData\Vehicles\AutomobilistaHUD.mas file before replacing it.
OpenWheel Damage GUID 1.0
Open Wheel Damage Hud for Automobilista