you can't. only way is to look at the car numbers:
Current roster: A cars are cab cars while C cars are intermediate cars with conductor controls only (no cab).
PA1: 100-151 ("C" cars), 600-709 ("A" cars)
PA2: 152-181 ("C" cars), 710-723("A" cars)
PA3: 724-769 ("A cars" only)