Fines should be prohibitive not conducive or measured against the value of the vehicle. If the vehicle had traveled for 10kms before it was nabbed and it was shown that the vehicle and such vehicles actually cause damage to the roads, then the fines should be weighed against the damage to the road or the cost of repairing the road and not the value of the vehicle.
If you found a person with a piece of metal, say a divider(Ile ya geometry set) scratching the paid of your Rolls Royce and you were to fine them, would you look at the cost of a geometric set or the cost of repainting the whole Car, you'd probably have to ship it abroad, be without the services of the car for a few months. If you factor all this and say you fine the idiot 10 million some might start saying it's too heavy a fine but to you it's cheap and you'd have to even fork out more money to fix the issue.