Hi, hopefully someone can help, a need has arisen to replace the front left lower rear control arm (the boomerang shaped one) as the bearing is perished.However, on browsing Autodoc/ECP/Halfords etc, there appears to be multiple versions available, differences being the cone size (12mm/14.4mm/16.8mm). Can anyone shed light on how to determine which one is required without stripping the current control arm from the car and measuring with verniers. Car is a 2014 A4 B8 S Line. Cheers.