On our first cruise last year we drove down from NE FL & had no problem following directions to the garage. The only problem came when there were no porters in sight, so we carried our 5 bags (luckily one on wheels, everything loaded on it or on us) down the elevator, couldn't find anyone (still) to tell us where to drop our bags & ended up carrying them ALL on board ship. As soon as we were on board someone took them & us to our cabin. We were embarrassed & knew we looked like first-timers, but we got over it.
Some passengers didn't get their bags til 10:30 that nite. The restaurants lift the dress code for departure day & you can wear shorts, since so many people don't have their bags yet. So, since we now knew we could carry all those bags, we picked them up at the terminal & carried them back to the car. We didn't have to wait in line to pay at the garage, so I guess it was worth that. We paid with a credit card, no problem.