https://turningbacktimecarshow.org/
Haven't been able to make this one in several years but signed up for this year. Usually a pretty large turnout of cool stuff that completely takes over the entire downtown area. Sycamore is close enough to the Chicago suburbs that it draws a good group of cars from that area along with many of the local small town stuff that isn't seen too much. Get there early if you want a decent space on the main street.