No...no ...no....Let's not jump to conculsions.....
The cone shaped spring
burdar posted is about 1.5" tall with an almost 2" diameter at the base. It's only found on Challengers not Cudas and serves the purpose laid out in his post.
HOWEVER
On the lower center mounting bolt of the rear quater window - track, there is a smaller cone shaped spring that is about 1" tall and maybe 1" in diameter at it's base. It goes over the shoulder bolt and holds tension on the bottom of the window assembly, while allowing it to move outward/inward a little.
Class dismissed