WRX front bottom Wishbone bushes.

On all my previous makes of car the front suspension lower Wishbone/Suspension control arms have had a Ball joint at the hub end then 2 horizontal bushes at the chassis end to allow the bracket to pivot up/down with the suspension.

On my 2008 WRX (first of the hatchback shapes) one of the back bushes is vertical and has a solid stud to hold it. Therefore, when the Wishbone needs to pivot the rubber has to flex. The rubber on both N/S and O/S has started to tear away from the metal.

What is the purpose of this "odd" arrangement and how does it achieve it?

Cheers. Mick.