OK so the cheap Amazon HUDs don't display NAV, (I thought that was what that 7" screen AND VOICE INSTRUCTION was for... )
For Us, meaning gear heads, I want to know my Temps, by Alt is working prop, and most importantly the Speed and RPM.
Especially in a BMW, where its hard to accurately access speed w/o looking. Even this $30 unit has "speed correction" to display true speed not the optimistic 8% + BMW Speedo...Warning Flashes and/or noises at user defined RPM, or High Temp Warnings. And the icing on the cake is it matches the gauges.
Heres a vid of me beating my "friends" rental car w/ this unit....Its visible during the day and looks much better in person...
Please stop with this BMW retrofit BS HUD, its insane. LOL