I find the best route, is to 'make 2d drawing' within Rhino, that has a good set of options for what lines are included, then print to pdf from the top view 2d lines only. - if this is already what you're doing, then look at the settings in Rhino for the make 2d drawing for what it is including, like silhouette, hidden edges etc.and try print to pdf or export to pdf, depending on which route you are currebtly doing. also try export straight to illustrator format again from the 2d drawing that rhino has made.