I made a simple tyre wear overlay, including temperature and brakes temps.
In the same space, two indicators for damage; suspension and engine.
They have a warning (orange icon turns visible) and a wreck indicator (red led turns on). I know it's not too accurate, but I think it's more like what you would see in your car (I hope you never see that IRL!).
The main advantage over the in game HUD is the ability to resize them.
I hope you like it! I'll keep adding more things as I get new ideas.