Carlisle

Sounds like you may be referring to the 'Kick-off to Carlisle' put on by The Mopar Rebellion club? If so, a quote from the Carlisle Events website;

"Free Thursday Evening Kick-Off to Carlisle
Hosted By Mopar Rebellion at the Carlisle Expo Center
The show may officially begin on Friday but the fun starts on Thursday with the Kick-Off to Carlisle party hosted by Mopar Rebellion. It is held at the Carlisle Expo Center at starts at 4 p.m. The expo center is a block west of the fairgrounds and is easily accessible by foot. If driving to the kick-off, you can input 100 K St., Carlisle, PA 17013 into your GPS.

The Kick-Off features inexpensive food, music, great Mopars and more. It is free for participants and spectators! There’s no judging – just fun with well over 400 cars. Be sure to arrive early before all of the spots are gone. Check out Mopar Rebellion on Facebook for more details on a fun all-Mopar event. "

Easy way to get there? Leave the fairgrounds via Gate 3 & proceed straight ahead, the Expo Center will be on your left, maybe a 1/4 mile or so.