prius with bluetooth navigation no rear cam mirror question?

the mirror I have has five buttons a 0 a 1 and three things that look like a house with different dots, I press the 0 but the green light keeps turning back on later on also if I hit any of the house buttons it makes a red flash. what is this for?
Also an other curious question is there any way to add the backup camera if I can get one or is the nav console just not equipped?
just curious, cause I'd sure like a backup cam without adding an extra ugly screen.
and sorry for all the newb questions, but does anyone know a source for just the resistive glass, I figure I can fix computers and cell phones on occasion I will be able to replace it.
If I can find a source.
terramir