You are incorrect. Having a signature on a MAP policy turns the policy into an agreement. This is a big No-No. Much of the power behind a MAP program comes from the fact that it is a unilateral POLICY and NOT an AGREEMENT. If you have a signature then you have an agreement and by making agreements with a dealer concerning pricing, you risk running afoul of the law!
Besides monitoring and MAP policy enforcement we also develop a healthy relationship with your compliant sellers.