I might have been one of the first SIAC members. In '79 I picked up a car magazine off the magazine rack and saw a letter to the editor from some guy in PA saying he and a buddy were starting a club for owners of AAR cudas and T/A Challengers. I'd just bought my T/A late in '78 so I fired off a letter and a SASE, count me in!
I have every newsletter from SIAC, stashed away in a plastic storage bin somewhere. I should dig them out and put them in a more accessible place! The thing I remember most from glancing at the issues in fairly recent times were the ads. Set of original wheels off T/A complete with rings and hubcaps, $30 each. Or especially an ad from someone in Canada in one of the issues, '70 hemi Challenger convertible. Minor rust in quarters. $12,000 FIRM!! Yeah, I had $11,750 burning a hole in my pocket and no way I could have come up with another $250 so I didn't even call.
Just kidding, I was a freshman in college at the time and $12K seemed like all the money in the world then.
The member roster showed a fairly large number of members from IL but I don't think we were very well organized here. Other than Mopar day at the nearest dragstrip not far over the WI border I didn't go to any Mopar events back them, if SIAC had sponsored something locally I would have tried to attend. Sorry that group eventually fell apart, it was a pretty good club. I remember those in charge saying it was a lot of work for not much in return, and in addition late night calls from irate members wondering why they hadn't seen a newsletter in a few months, other assorted grief, etc, and that's why after 5 or 6 years they pulled the plug on it.