I run the same event with a detuned Tomahawk S. (24min of Nurb)
Set it to "push the pace" and forget it. 27min later restart. I've done this to the point the engine and chassis are both degraded and taken big pp loss. I just turn up the power limiter and never fix it or change oil so the car is always 650pp this is how I've been farming my cash
In December I set myself a new target, to own every car in the game. After about 3 months this became a real bore. Then along came B SPEC. What a godsend. My own personal favourite grind is Like the wind 3 with the 15th ann Huayra. Now I spend 1 morning a week grinding and rolling cigarettes. 1 morning a week grinding and buying new cars, and 5 mornings a week grinding and reading a good book.Only 100 more cars to buy, its great.