A CRG article pointed out information about a radius rod that were installed by a dealer:
A significant complication to the analysis of the radius rod applications is the rectangular radius rod service retrofit kit. This makes it a bit more difficult for us to be sure if a rectangular bar was factory installed or dealer installed. However, by comparison of the service replacement instructions with the original factory assembly instructions, it appears that there are three clues that should distinguish a service replacement rectangular bar from its factory brother:
When the service kit was applied to a car with no previous bar, the body bracket was welded to the body, rather than bolted-on as was done at the factory.
If the axle bracket didn't have holes to mount the stop bracket, the service kit required the bumper stop bracket to be welded to the axle bracket, rather than bolted-on as was done at the factory.
When the service kit was applied to a car with a pre-existing round bar, the round bar axle brackets were not replaced with the new brackets but remained on the axle and were used as-is. The two bracket types have distincly different shapes.
