From the Nokia Developer Automotive Blog:
"There are two versions of the Nokia Car Mode available, depending on the user preferences and availability of MirrorLink enabled car infotainment system on the region.
The first version of the Nokia Car Mode includes the MirrorLink and could require the user to update the phone software, http://store.ovi.com/content/234058
The second version of the Nokia Car Mode is provided without the MirrorLink, giving the user a good chance to get familiar with the Nokia Car Mode before MirrorLink enabled car infotainment system is available or before making a purchase decision, http://store.ovi.com/content/232236
Marko Tuukkanen, Senior Product Manager, Automotive, Nokia