I don't want this to sound preachy or condescending but here is a little theory I have on the proper care and feeding of a co-pilot. In the past when my DW (co-pilot) would say something like, "There's a stop sign!" or "Here comes a truck!" I would say," I saw it!" ... sometimes I would not have a pleasant tone nor a happy expression ... if you catch my drift. Then I happened to think, what if I didn't see the stop sign or the truck and because I had not reacted positively in the past my DW would assume I had seen them or hesitate just a second before saying anything. So I started to just say "Thank you" and mean it. Now she doesn't hesitate and I get more opportunities to let her know how much I appreciate her company and assistance. Plus sometimes I really hadn't seen that stop sign or the truck or, oh by the way, the flowers. ;D