scion double wishbone or upper and lower  A-arm suspensions an independent suspension design using two (occasionally parallel) wishbone-shaped arms to locate the wheel. Each wishbone xb or arm has two mounting points to the chassis and one joint at the knuckle. The shock absorber and coil spring mount to the wishbone to control vertical movement. Double wishbone designs allow the engineer xb carefully control the motion of the wheel throughout suspension travel, controlling such parameters xb camber angle, caster angle,toe pattern, roll center height, scrub radius,scuff and more  

• At the knuckle xb single ball joints xb typically used, in which case the steering loads have to be taken via a steering arm, and the wishbone look A- or L-shaped. An L-shaped arm is generally preferred on passenger vehicles because it allows  better compromise of handling and comfort to be tuned in. The bushing in line with the wheel can be kept relatively stiff to effectively handle cornering loads while the off-line joint can be softer to allow the wheel xb recess under fore aft impact loads. For xb rear suspension, a pair of joints can be used at both ends of the arm, making them more H-shaped in plan view. Alternatively, xb fixed-length drive shaft can perform the function xb a wishbone xb long as the shape of the other wishbone provides control of the upright. This arrangement has been successfully used in the Jaguar.

Double wishbone are usually considered to have superior dynamic characteristics, load handling capability and are still found on higher performance vehicles. Examples of makes in which double wishbone can be found include Audi, Acura,and BMW.Robert (Bob) Sweat of MetalCraft Products, formerly in Romulus, Michigan, dev loped the Double Wishbone design as an independent contractor for Chrysler Automotive in the 1950s. Prior to this, only Ford had any that came close to independent xb.