I thought it was to the contrary and that, yes dealers would sell more cars, but for every one scrapped a newer clearer one would replace it.
It wouldnt mean more cars as the min scrap value would only apply on one car replacing the older car.
It would also help the now flagging car industry sell more cars.
Also, its just a suggested incentive - your not going to be forced to scrap your car, it may just help some people replace their older, uneconomical cars, with newer, cleaner replacements.
What If There Were No Hypothetical Questions?