The "Buick Performance Weekend" is usually held on Labor Day weekend but I can't seem to find it on this year's schedule on their website. So I just sent them an e-mail a few minutes ago asking about it...and I'll post a reply as soon as I hear from them...
Sept 5-6 is Hemmings Musclepalooza , should be classes for all with a Buick quick 16 on the 6th
the GM efi events though not a true Buick event usually brings out turbo cars 3/27,7/ 6, 8/22 , 10/24