At KC Summers, We're Family! KC Summers has been located in Mattoon for over 40 years. KC Summers has been family owned and operated since the beginning, offering a unique ownership experience that you have to see to believe. We offer a wide selection of high quality preowned and new vehicles. Please visit us at our downtown GMC, Buick, Toyota, Scion and Hyundai and our Nissan Mazda store on South Route 45 in Mattoon.