NG 900/9-3 Rear ARB
Replacing the rear ARB is one of the easiest and most effective methods of improving the handling of the 900 and 9-3. Mounting a thicker rear ARB reduces body roll in turns, improves stability and traction during acceleration, and reduces understeer. Rollbars of varying thicknesses are available from Genuine Saab.
Double Stacked Stock ARBs
A more inexpensive option is to double up stock rollbars. By using two stock ARBs and four grade 8 3/8" bolts and some 1/2" clamps you can cheaply improve you handling.
Additional information about selecting the correct rear ARB can be found on the [Trolltuner site]
When removing the stock ARB the stock bolts will more than likely only come off when they snap due to rust and age.