rear control arm or rear track arms.

[lavagate]

The road bumps have become increasing louder and the time has come to replace either the rear control arms or the longer rear training arms. From everything I've read the solution is to replace the control arms. So I called the Porsche dealership and they say the solution may be the trailing arms. Does anyone have a opinion.

I understand the nylon bushings on the control arms become hard and wear out, thus creating a more noticeable noise with road surfaces. What do the trailing arms do besides assist track control which my 99 Boxster does not have.