Some candidates are allowed to drive their personal vehicles to OCS, some aren’t. You need to check if you are allowed to drive. If you have the option, definitely drive.
First of all, when liberty comes, you won’t have to find a ride off base or into Q-town. Second, you won’t have to worry about getting a ride back for your firewatch. When I was at OCS, 4 people missed their firewatches during the first weekend of liberty. I know at least one candidate said he “couldn’t find a ride.” Don’t be that guy. Finally, you can keep all of your extra gear in your car that won’t fit in your lockers.
Here is an extra tip, stock your vehicle with your favorite junk food. When your platoon is released for their first liberty, invite some candidates to your car for some delicious gedunk.