I dont think being a P-plater is the issue to be honest. Im sure a lot of P-plate drivers do the right thing regardless of the car they are in whether it have 50 hp or 150
Anyone, of any age, in any car, can & will speed IF THEY FEEL THE NEED TO.
It just so happens that modified cars stand out, therefor people will clearly remember a modified car doing 80kms in a 60kms zone over a family sedan doing the same.
Its just how it is unfortunatly.