That's correct, I wonder what happens if you have will call tickets though... Anyone know when the parking lots open?
According to TM page Will Call opens two hours before the event...
when TM pre-charges everyone for parking, they generally don't check on the way in - you're waved through. the assumption is that everyone has already paid... a vlid one, unless you're there just to tail-gate (but i suspect that someone calculated that it wasn't worth the cost/effort of screening out the few party crashers).
so even if your tickets are will-call, you shouldn't have a problem... other than traffic on the way out.