You could have progressive congestion pricing based on the value of the car. I didn't look at it, but what I think you're saying is that this is a regressive pricing control.

I think that's an important point: regressive taxes/fines shouldn't be used to control behavior as it disproportionately impacts the less affluent*

But a progessive scheme is more involved - it might require using the value of the car for example as a basis for the pricing. But I suspect it could be done.