Plan to go to Sycamore Chevrolet GMC’s Trunk or Treat this Saturday, October 21st from 2:00-5:00pm. Get your best costume on and get in on the contests! Trick or Treating and Costume Contest Costume Contest Winner announced at 4:30pm. Free to attend to all in the community! DeKalb / Sycamore Chevrolet GMC is located at 1925 Mercantile Drive in Sycamore (next to Portillos).