S.D. Codified Laws § 32-6B-57
It shall be unlawful for a franchisor to offer to sell or to sell any new vehicle to any franchisee at a lower actual price therefor than the actual price charged to any other franchisee for the same model vehicle similarly equipped or to utilize any device including, but not limited to, sales promotion plans or programs which result in such lesser actual price; provided, however, the provisions of this section shall not apply to sales to a franchisee for resale to any unit of government, federal, state, or local. Provided, further, the provisions of this section shall not apply to sales to a franchisee of any vehicle ultimately sold, donated, or used by said franchisee in a driver's education program. Provided, further, that the provisions of this section shall not apply so long as the franchisor offers to sell or sells new vehicles to all franchisees at the same price. Each and every person who violates this section shall be guilty of a Class 1 misdemeanor, and each and every person violating this section shall be liable thereby for all damages caused by such violation.
SDCL 32-6B-57