George,
The bulb that's most likely bad is in the rear. If you access the light panel from inside, it will be the 3'rd bulb from the bottom. It is difficult to notice if this bulb is out because there are 2 bulbs lit on each side when the car is running. The bad bulb is the one on top where the light fixture narrows, in the middle of the fixture. Although I've had to replace this same bulb on my 01 V70, recently my bulb warning light came on so I removed the bulb and the filament appeared OK, so I reinstalled it and it worked fine. I suppose it was just a bit of corrosion preventing a good electrical contact. If your failure light is intermittently coming on, I would recommend replacing the bulb. I hope this helps.

Wayne Stephens