While cleaning up and painting the front suspension on my '67 Cadillac convertible, I found a small braided copper ground strap attached to each upper control arm. They appear to be original equipment. One end of each strap is connected to the rear control arm bolt that goes through the bushing and the other end is connected to the upper control arm by a small machine screw. It seems that the purpose would be to establish an electrical connection between the upper control arm through the bolt to the lower control arm, which would otherwise be isolated by the bushing, but why would such a connection be necessary? Prevents static buildup, maybe? I'm sure the factory would not have spent the money to add these grounds if they weren't needed, but I'll be damned if I can see any reason for them. Just curious.