Keeping the arms parallel minimizes binding of the suspebsion when one wheel tries to move up or down relative to the other, as happens on cars that turn corners and drive on bumpy surfaces. Angling the arms relative to each other, as is done on drag cars, results in geometry that is essentially the same as what ladder bars provide. Adjusting the links on a drag car is functionally the same as changing the length and/or front mounting poit of a ladder bar. That suspension is basically a hinge. Fine for going straight, bvad fior anything else. Like ladder bars, when the links aren't parallel something has to flex, or bend, or have compliant mountings, to accommodate independent wheel movement. With drag racing suspension there is a momentary upward force on the chassis. Where on the chassis that force is concentrated depends on how the suspension is set-up and adjusted. Beyond that, the only way for a torque are to lift the front of the car would be if the wheels were held from rotating. Wheelstands are a function of where the car's GG is relative to the rear wheels, and how hard the car accelerates. Wings probide downforce, but that also have drag. The higher a given wing is mounted, the more weight it takes off the front end of the car. It the same principal with air(center of pressure) as with the CG.