A spacer at the top joint can help with handling,

Sorry for the hijack, but this is interesting. Can you explain why this is the case?
Steve.

The best handling vitara I have driven had a calmini kit in it. The calmini kit raises the front roll centre heaps but the rear very little. Whilst tall and soft, it feels very intuitive - like a normal car. Vitara's generally feel terrible so it was a revelation to me.

Steve.

No. Roll stiffness and roll centre are different things. Adding roll stiffness with a sway bar would increase oversteer, and vitaras need more oversteer like a hole in the head.

Steve.

x700, push into a corner that is a lot tighter than you thought and get ready for the giggles, at least they will slide pretty tamely once they let go

No. Roll stiffness and roll centre are different things. Adding roll stiffness with a sway bar would increase oversteer, and vitaras need more oversteer like a hole in the head.

Steve.

x700, push into a corner that is a lot tighter than you thought and get ready for the giggles, at least they will slide pretty tamely once they let go

How does this work Steve?
I only ask because in my experience with sway bars I have found that fitting* one to the front increases oversteer and fitting* one to the rear increases understeer.

*Fitting one where one never existed or upgrading existing.

This is contrary to both suspension theory and normal experience, and without knowing what car you were experiencing this with, I can only assume it was due to an inherently mismatched or poorly setup car from scratch.

It's possible that adding a front sway bar might increase steering "bite" and therefore the speed of turn in, and therefore increase the speed the car transitions to oversteer, but I'm guessing that that's in a car that already has quite stiff rear suspension/high rear roll stiffness and was already prone to oversteer.

It's also possible that fitting a rear sway bar might reduce body roll to an extent that the car sat flat enough to keep its front tyres loaded better than therefore understeer was reduced.

However, as I've said, this must have been a strangely set up car to start with, but I'll also add it's important to separate "turn in" from the activity of the car through the corner.

I'll use the example of Piggles. With high rear roll stiffness, (radius arm rear) and relatively low front roll stiffness ( OME front leaf) my car would turn in very quickly ( understeer reduced, I guess) but would then transition to oversteer very quickly as the outside rear tyre was overloaded and the inside rear tyre would go light.

Doing nothing other than removing a radius arm bolt - so NO parameters have changed except roll stiffness, the car would turn in slower but once into the turn it was almost impossible to oversteer - the car would lift an inside front wheel and the resulting overload of the outside front would push the car into understeer. It's actually nicer to drive like this, but not as much fun.

Now coiled front and 3-link rear it's still prone to understeer which is exactly what the theory says it should do.

I've had the same experience with my Gwagen - removing the front sway bar massively improved turn in and reduced understeer.

Steve.

The best handling vitara I have driven had a calmini kit in it. The calmini kit raises the front roll centre heaps but the rear very little. Whilst tall and soft, it feels very intuitive - like a normal car. Vitara's generally feel terrible so it was a revelation to me.

Steve.