Granted I'm only 23 but I specifically remember one dark evening during a blizzard (1997, I think) when the mom and I got caught by a train tjat was seemingly comprised entirely of autoracks at the Lapeer Rd crossing just south of the yard. That's the most specific example I can give you, otherwise I do remember seeing the rollingstock in dedicated unit trains and mixed freights.
Also, after a bit of research, I found out that CSX operated a Saginaw to Philly train symboled Q396 which carried finished products as well as parts.