ALMS, FIA Sports Car, and ACO use three vertically-arranged lights forward of the rear wheels to show position info. For example on the DBR9, the lights are here:



Or if you look at this Audi R8, the lights are the three black circles in front of the rear wheel:



This is IMSA's competitor bulletin for the system in ALMS: http://www.imsaracing.net/2003/competitors/cb04-03.pdf

I don't think Grand Am uses this system, but I could be wrong.

As for the which series the DBR9 will race in, it will at the very least run in ALMS. See this article for reference: http://www.imsaracing.net/imsaNS.cfm...471048ALMS.htm