SF90 Navigation Help

Hi. Can anyone tell me where the NavigationSD card is located. Or is it prebuilt in the software. I am about to take it on a road trip through central / South America but it appears that as soon as i leave the States the navigation just shows a light blue screen. I asked the stealership and they didn't know / wouldn't tell me... but for a fee they would look LOL. Hoping that it is just a SD card switch out. The other question is if it is a SD card does anyone know where i could find these at non dealership price.