Fine should be scaled to your income and have an escalating multiplier for reoffense within the same category of offense with a cool down period of a few years if they don't break the law.
I've brought this up many times online and people usually reply with something like "lots of people who have no income on paper but are wealthy speed" and a recent solution that I've seen posted is to scale the fine to the value of the vehicle.
Quite often fines are a pretty limp and ineffective way of modulating an individual's behaviour which is ultimately a choice by society.
We can make a better choice there to induce the behaviour that we want from antisocial people.