Please keep the realism!

[IbanezLaney]

Just think about the old mechanical speedometers from back when cars were good.
This works the same way. The needle bounce seemed way over exaggerated.

A very slight wobble seems correct and only a large wobble would occur if the cable was incorrectly installed or damaged. The mechanical type would snap eventually if this was the case.

I don't know much about the gauges from back then but I would be surprised if they were not oil dampened to further reduce wobble.