The C.A.R. Residential Purchase Agreement. Contra Costa County Bar Association.Most standard form purchase agreements include two alternative dispute resolution provisions: arbitration and mediation clauses. In 2020, at the end of the lease, they signed a Retail Installment Sales Contract (RISC) with the dealer to finance the purchase of the vehicle. Unless you are prepared to pay cash in one payment, you will sign an arbitration agreement to buy that car.