This part shall be liberally construed and applied to promote its underlying purposes and policies, which are as follows:
(a) The prohibition of discrimination based upon any characteristic listed or defined in subdivision (b) or (e) of Section 51 in the granting, sale, transfer, bequest, termination, and nonrenewal of dealerships.
(b) The requirements of this part shall not be varied by contract or agreement and any portion of a contract or agreement purporting to do so is void and unenforceable.