To go back to the original question, I live in the UK, have a '97 V70 and
experienced the same problem soon after I bought it in 2000. I changed one
headlight bulb, then another would go, and so on. Eventually, I took advice
from the (very experienced) Chief Mechanic at my local Volvo dealership, who
recommended I change all four (2 x dipped and 2 x full beam) bulbs at the
same time, and with Volvo bulbs rather than generics.

I took some convincing, but eventually did as I was told. Whether by fluke
or not, I have not had another bulb go in the last four years, and I run
with daylight running lights on (travelling regularly on the M25 around
London, I'll take any help that's offered in order to be seen......!)

Bill

I enjoyed you view.

If you put fuel in the tank when it is near empty why not change a bulb that
is burned out. So the bulb is expensive. So is the gas.

The daylight running lights are to make you more visible so those less
safety conscious non-volvo drivers have a better chance of not running into
you.  This has nothing to do with you driving ability.

I have been driving my XC70 for 3 years and have spent $0.00 on burned out
bulbs of any kind.

BTW using lights in the day time was started by motorcycle gangs as a means
of increasing there visibility and survival.

Putting this another way to save $20 you would increase your chances of have
an accident?
(Dealer Parts says $15.49 plus tax)  The dealer has to download software to
update the computer.
BTW I asked my service IF he would do this and his diplomatic answer was
"NO!!!!!!!!!"

Actually I do not drive with daylight running light on at all, I use my
lights all of the time.

Cheers