ALMS introduced the use of a position light system, 3 little lights that would indicate the position in class of each car in the top 3. They can be seen in front of the rear tire below.
(Photo from ALMS.com)
Well the newly merged USCR has taken it to the next level. How about an iPad sized full position indicator?
(Photo from Marshall Pruett at Racer.com)
The boards will be mandatory on all cars.