Another thought... I think we need longer than 15 mins for qualifying. The out lap will take 9:30 odd, and the flying lap will be a similar time. Thats 19 minutes there. The people at the back will not start their flying lap until potentially the 11 minute mark, so add the 9:30 to that... and you are looking at 21min mark for the final drivers. So qualifying will needs to stay open for the final drivers to finish their lap. I'd suggest a 18 or 19 min qualifying + the 3 minute buffer to allow all drivers to finish.