Aluminium wishbones

[colesey]

The advantage of the alloy arms is mostly lighter weight (@1.5kg) which is also unsprung. You could always add the matching alloy hubs at the same time for further 2kg of unsprung weight saving per side and slightly quicker steering (rod mounting point is a little different).

[pudding]

The other advantage of aluminium is NVH reduction and rigidity    Alloy castings bend less than pressed steel when driving hard.  The cast steel arms on the GTI are actually far better than the cheesey pressed wishbones the poor old MK7 and MK8 are afflicted with.  They're just heavy.

The Passat alloy knuckles widen the front track a little as well.  With the whole compliment of alloy parts and decent suspension, ARBs etc, the cornering is quite impressive