HUD Research

Most racing games seem to have HUDs that only occupy the corners and very edges of the screen. They also attempt to be as transparent as possible for least obscured viewing space.
Games like:

Forza 5

Need for Speed: Hot Pursuit

Mario Kart

For my HUD for my own racing game I'll do the same with my space, but will also use it to help theme my level. 

My own vehicle's speedometer looks something like this: 

And also this:

Probably a little too industrial for my country level.

Really what I'd like to do is stick all those dials on a piece of wood:

Perfect.