I'm about to install an aftermarket head unit (Corksport kit).

I read on some other random site that the factory navi sound won't work without the mazda head unit.

Anyone know if that's true?

 

If this is true you could use the navi LCD as a second monitor. But I mean wouldn't most 2DIN units have navigation?

 

The navigation your going to get with most aftermarket HU is going to be WAAAY better than what you would get from the stock navi anyways.. if you HAVE to have the second screen.. i would make it a carputer screen or something... but a seperate navi isn't a good idea IMHO