Wayne,
I kind of figured it may have to do with the fuel spills they have had in the past. But just think what a fire they could have if two of the cars crashed just right and caused one of those full fuel cells to explode.
As for the spoilers, I saw on one of the sites the other day that they will be at a 70 degree angle and the teams won't be allowed to adjust them.
EDIT: Just saw this on the NASCAR site. The spoilers will be on the cars starting the 28th.
http://www.nascar.com/2010/news/head...lle/index.html
Ron