Both before Oct 1st, sorry. Not huge events or mopar specific but good times:
Springfield Mother Road Festival
Sept 26 ..... 6pm - 10pm
Sept 27 ..... 11am - 10pm
Sept 28 ..... 11am - 2pm
I remember the yearly "Jacksonville Cruise Night" to be a good time. I haven't been for a few years but it is a rather large draw for a small town. Not terribly far from you.
Jacksonville Cruise
Saturday, Sept. 20th