Thanks for bringing this up. sorry I'm late to the party. this board doesn't get much action for the S85 engine. I just did the carbon delete, need to look at those RPI scoops.
Do you still have your beast?I'm not sure about this, as RPI did not mentioned any tuning, remapping or ECU flashing after installing the scoops. There was a dyno before and after which showed a 15-17hp gain. I've done this mod and I can tell you there is without doubt a "feeling" of increase in power. I only say feeling because I don't have a dyno to prove it. Also, I was never implying there would be a significant increase in power. At best you'll upgrade to a 20-30 hp gain. That's a 4-6% increase which is not significant relative to the base 500hp, but is certainly noticeable.
There are some other cheap cosmetic upgrades I can recommend, but those are personal taste and may not be to everyone's liking. These basic performance mods I recommended here were covered thoroughly in several M5 Board threads, the general consensus was that they are the best no-brainer bang for the buck performance mods, especially the carbon filter delete which is literally a free mod. Many over there felt these were must-do mods. In the grand scheme of things, $300-350 isn't going to make or break anyone's bank when comparing other parts or regular maintenance on these beasts.