I don't remember what kind of primer it was. Just a spray can from my local parts store. All I remember was that the first one was a normal primer, and the second (which was recommended after the first one bubbled) was self etching. This is the "some primers don't mix with some paints" thing you were talking about.
The paint on the car is not original (it's a 67 Camaro) and I have no idea what type of paint it is.
I will try to find an "epoxy" primer and spot test it. Any idea if it's available in spray can just for testing (I know a paint supplier, so will get the good stuff when I do the whole car).