I have a s5 coupe and bought a set of s4 A arms so that I could have replaceable ball joints. Now the question which arm goes on which side? I have one stamped OA and another OF....I was looking at the rearward bushings and it gives me a general idea but I wanted to make absolutely sure. I searched the forum and really couldnt find anything. (I already know I need new sway bar end links and I also have new bushings as well)

 

Have you tried looking at a Haynes manual? They usually have under-carriage shots of the vehicle, and that may help... There are no other identifying marks on the a arms anywhere?

 

There is a bracket that sticks up for the steering knuckle to bolt to. The bracket faces up towards the sky. That should help you figure it out.

 

The flat part of the REAR bushing faces up towards the sky.

 

Just for everyones info I figured it out. The passenger side is stamped OA and the drivers side OF.