It was actually the second mod I made to the rr suspension (Rod end rr end links 1st), but boxing in the main rr control arm gives very impressive results in that it improves the handling AND the ride.
WHY? The stock lateral arms, toe control and the main ones, deflect and deform under load. Although the main arms are fairly robust in their design, especially compared to the absolute crap toe arms, they can be easily improved by simply adding boxing plates. If you look at what the OEM manufacturers are doing currently with body-on-frame chassis, they're fully boxing the frames and achieving quantum leaps in rigidity over the same frame in unboxed form.
I should add that this mod specifically addresses torsion loading which is what your chassis and suspension sees during cornering.
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.
| 
Ah I hate rust! All the neat mods that can be done with no worries about it wasting away. I'll send you PM approx cost to do the suspension mods. I'd love to find one of those anode systems that would slow down the galvanic/corrision? That actually works!