Zulu4 said:
except for the phaeton those cars are all in base fwd design and the phaeton is an A8 platform so also not a rwd car.
As I said it's common on older RWD cars, it makes sense that your cars don't have them as they're not RWD platforms.
But it's common in BMW, mercedes, lexus, some jaguars, porsche etc from the pre electronic handbrake era, so not at all uncommon (for base RWD platforms)
I don't know why they use this setup though.
I think it goes back to an era that cars in general had drum brakes (especially at the rear), and that rwd cars in general were the first cars that used disc brakes all around because performance cars used to be RWD in general. (I'm talking about the 60's/70's here).
I think the separate handbrake caliper goes back to that era too.
What also is a reason is that a handbrake setup in the calipers is not possible (or virtually not possible and not compliant with the rules) when you have multiple piston calipers (so pistons on either side). This again is only applicable for high performance cars as only those tend to have such a setup, especially at the rear.
Somehow RWD platforms tend to have different brake systems to FWD/AWD platforms. The way the systems are split is usually also different for some reason so that's another difference. FWD tends to be diagonally split and RWD tends to be front/rear split.
But there are of course also RWD base platforms that have the handbrake in the caliper. A Mazda mx5 for example.
I'm learning.
