I drive a '13 Sentra and the light that shows what gear the car is in near the shifter has been going in and out. Any advice other than just replacing the bulb outright?

Check how tightly the bulb gets held, I've run into more than one Nissan issue now with the ultra cheap thin gauge metal used to hold them. I've resorted to using like simple cardboard cut to shape in a couple of spots to shim the connector blades up to make them hold the bulb tighter and problems solved. Some you can simply rebend tighter with needlenose pliers to do same. The bulb heat lets the contacts relax to make contact half the time or not at all.

Bulb can of course simply have a broken filament that touches then doesn't too. That loose contact thing I now look for anytime I ever pull a bulb, todays' lighter gauge materials (to reduce car weight) demand it.