The latest parts I sprayed with Classic Coat don't stick very well either.
Yesterday I got my order from Summit. I ordered the SEM Soap, SEM Plastic & Leather Prep, and since they don't have the Color Coat in spray cans of Very Dark Pewter, I instead decided to order the graphite color in the Color Coat.
I decided to start with the small center console that goes on the roof. I had already painted two other ones I have that the Classic Coat wouldn't stick to. So for this one I used the SEM Soap with the gray scotch bright pad to scrub the part and then I rinsed it with water. I left it to dry and then came back and wiped it down in one direction with the Plastic and Leather prep exactly how they tell you to. Then for good measure I took a tack cloth over the part. Then I sprayed a light coat of the XXX Adhesion Promoter and let that flash for 5 minutes. Then I sprayed a wet coat of the XXX and let that flash for 15 minutes. Finally I sprayed it with the graphite Color Coat. This was done at 2am.
Around lunch time today I looked over the part and it looked great! I could feel the little bit of difference between the one that I sprayed with Classic Coat, and this one that I sprayed with Color Coat. I took it upstairs to my wife and I had her take her finger nail and lightly run it over both parts. None of the coating came off on the one sprayed with Color Coat, but when she did it to the one in Classic Coat, the coating came off, just like every other part I've sprayed so far with the Classic Coat.
Now the graphite and very dark pewter are obviously different colors. I honestly like the graphite better and since I redid my headliner in black it really doesn't matter to me that the plastic parts above my head are now graphite while the rest of the truck is very dark pewter.
So long story short, in my case the Color Coat definitely adheres to my pieces while the Classic Coat does not.