The position light is probably one of the two bulbs in one of your tail light assemblies. I have a V70, but the setup is probably pretty similar. You'll be able to tell at night, or out of direct sunlight, but one of the tail lights won't look like the other. Good luck, as changing mine is a contortion and requires some patience. Take out the burnt one and match it. I carry one or two spares now, as they don't seem to last too long.