It seems the main motivation for double points at PPIR is to increase attendance and more importantly cover the expenses of the weekend. I think a better solution would be to award "Bonus Points" (say 25 points) to every racer in each class he registers and pays for. Then allow the actual racing to decide placements with the same reward and penalty as every other round the racer attends instead of for ex. dropping from 1st to 7th on the last weekend of the season when you take a rock to the radiator in your 1st race and lose 72 points in every other race you miss that day.

I personally don't see how this or the double points will help attendance much at PPIR since the people in points battles are showing up anyway and the other people who aren't showing up don't care whether they lose 36 or 72 points - especially at the last race of the season.