If you want to avoid crowds go to DL.
If you want to be part of the opening day go to DCA and expect huge waits in line.
What I wrote in another thread is because people will start lining up at night, if you want the short wait for Radiator Springs Racers get in the lineup at 4am, and 6 hours later around 10am you should be on the ride. It's just an educated guess based on what I know about how RSR will operate and what has happened with other major attraction openings.
RSR will have FP if it's in use expect all the FPs on opening day to be gone in 30-45 minutes and be taken by people who were in line by 12am at night.
Another option for RSR is to wait until night and just before the park closes get in line, this could could mean only a 2 hour wait assuming you can stay up that late.
Luigi's Flying Tires will probably have a 2-4 hours line. Mater's Junkyard Jamboree 1-3 hours. Compared to RSR, that may sounds good, but they aren't as nice an attraction as RSR.