Crazy idea

Too impractical. Too much unsprung weight. Compare the weight of a torsion bar compared to a coil spring. Coil springs can also be variable rate, giving you more load carrying ability with less weight & space. Also you would need to have some sort of moving arms to link a solid rear axle assembly to the t-bars. More added weight & parts to take up space. Then there is the lateral stability problem & also fore & aft movement of the axle assembly. How would you control that? By the time you'd be all done a Leaf Spring rear suspension woul be far superior.