Disneyland, unlike WDW, does have parking fees for regular hotel guests ($40 a day for self-parking). However, DVC Members staying at VGC are not subject to the fee and have free self-parking (valet does cost). For both hotel guests and DVC members, you can keep your car parked at the resort on the day you check-out until midnight. What I do not know is what could possibly happen if the car is there after midnight, e.g., you do not come back to pick it up until 2 a.m. on the 1st. I assume you will likely be fine since no-one at Disney is likely to take notice and do anything, but technically, once Jan 1 begins, you no longer have any parking rights at the resort, and Disney could just have your car towed away.