We have an 18 Murano SL purchased 4 months ago. During the two test drives the salesman explained how the Murano does not have what would be considered a lane departure warning system like the 18 Rogue we drove had. He explained that the vehicle does monitor lane departures and will show the cup of coffee symbol alerting you to come back to the center of the lane. Our salesman has left the dealership and no one there can help explain why our system really does nothing to alert us about lane departures. If I deliberately drive over the lane line several times I might randomly get the cup of coffee warning. The dealership said that this is all it's supposed to do. The owners manual really doesn't explain this system very well. My question is this, Is the cup of coffee symbol mostly useless or is ours malfunctioning. Thanks for the help.