I do believe that the arms you're referring to are not the trailing arms. Do they extend back and forth on the long axis of the car or from side to side (laterally)? The arms which are most commonly bent by the non-knowledgeable are the toe control arms. These are flimsy steel stampings and are the most easily accessible as they are the furthest towards the rear of the car and therefore easy to jack on, pull on, etc. I have seen many, many bent ones in my time - even Ford mechanics do it!

As for stronger ones check out my post "tubular toe control arms". Ford calls 'em rearward rear control arms and the main rear lateral control arms (stamped C section) forward rear control arms. The main arms can be strengthened by welding "boxing" plates on the open portion (bottom) which really helps ride AND handling. However, the rr subframe must be dropped to remove and reinstall them. The toe control arms, on the contrary, are easily removed and reinstalled. A rr alignement is recommended after.

Redcoat Raceworks. Performance parts and custom fabricating for Contours, Mystiques and Cougars. Specializing in chassis and suspension parts. Custom end links, control arms, strut tower bars, engine torque braces, etc.