From past experience in the netKar days, reverse grids do lead to trouble. The fast guys barge through from the back, elbows out, and after a lap or two everyone's in their ”natural” order. I've seen it time and time again. What did work better is reversing only the top half of the field. What could also work is reversing both halves e.g. reverse 1 to 12 and 13 to 24. One thing that sucked though, was if you DNF'd the race, you'd start from the back and effectively blow 2 races. What I would do is reverse the grid based on qualifying order, not race finish position, say even qually of race 1, and probably just for race 3 too, just to add some spice to the final race.
I can't make an app of this, because I've altered the server - this has to remain private.