It's per car, but it's for charity so any additional donations would certainly be welcome!
Sprints are run by QR not by the club, and there is no requirement for doing QR before lakeside or anything like that. However, I'm not sure if the people coming on the cruise will get to lakeside in time to enter the sprints as well:
Also, my personal recommendation is to give QR a try before doing sprints at lakeside, lakeside is dangerous. It does depend on your track driving experience though...