I've learned, through inadvertence, that the circumference of the bottom of the cup holder in my auto is 72mm. The correspondence between its circumference and the circumference of the cap of my favorite lens is near enough to render both the cup holder and the lens cap useless. The two are perfectly mated, and the physics of the situation dictates that efforts to remove the cap serve only to further lodge it.
How can I reverse the process?
Needlenose pliers? No.
Precision electronics screwdriver? No.
X-Acto knife fitted with No. 11 fine-point blade? No.
Nail file? No.
Duct tape? No.
Suction cup from Pottery Barn shower caddy? No.
At this point, I’m hopeful but doubtful that as temperatures rise the cup holder will expand and the lens cap shrink.