I have a aftermarket intake grate ( I was told that it is a Riva, but don't know for sure) off from a 2006 RXP and at the rear part of the ski there is the normal 3 holes that hold the grate on and then there is a extra 2 holes, I have no idea what these holes are for. The person I bought the ski from lives out of state and I asked him and he said that they are there for no reason. I was wondering if some one could shed some light for me and tell me what these holes might be there for. The holes are tapered.