In reading the replies below I would agree with most. One can't train attitude or hope. It is an internal trait. We may be able to help nurture it... I agree it is of the greatest importance!
We can teach the tools (steps). We can help with rapport building by teaching the ??s.
I feel though that the one thing we must do is continue training. So my answer is not to leave the salesperson, but remain with them throughout their career. If we are in, and out of a store then we also need to train the managers. No sales person is ever finished learning. (myself included) We must help develop an environment where this philosophy is adhered to. Open doors, constant training, and the removal of the fear to ask ??s. As Trainers, Dealers, Managers, we are above all teachers. If we want our people and ourselves to be successful the teaching/learning process must never end.