Which map are you using? If you're getting straight lines, the map is selected and the global map isn't selected then the map cannot be routeable.
BaseCamp can only display one map at a time, from your description you appear to have individual country maps, you need to use a map that covers all the area where you want to plot routes etc
Having problems with your BMW navigator 5? then please post here with any sat nav, software, mount or cradle problems.