Welcome to the County of Riverside Vendor Registration Portal. Common Elements of a Vendor Contract​​ Accurate description of goods and services.We'll help you craft the best vendor contract agreement for your specific needs, and help you manage that relationship as long as you need it. To work with us, you'll need to first register as a county vendor. Click here to visit the Riverside County Purchasing and Fleet Department. The E-Commerce Vendor shall use E-Commerce Vendor's best efforts in the performance of E-Commerce Vendor's obligations under this Agreement. We're a fast-moving company that encourages creativity, innovation and a focus on providing the best service to our customers. Cox Automotive is the only company in the world that offers a complete set of solutions for the automotive dealer. This contract has the option for lease and purchase. Term of Contract- Three (3) years with options for up to two (2) years.