Short bulb life is a Volvo hallmark. I had the identical experience with my '98 S70. Unfortunately, the new models are even worse. I have a 2001 S80 now, and replaced a headlight capsule and 2 tail light bulbs during the first 4000 miles. Some owners report free replacements during the vehicle warrantee period, but that is not the case in my area. Dealers here will replace any bulb that is less than 90 days old, but still charge for labor ($12 for a headlight capsule change). Plus you have the inconvenience of making an appointment and leaving the car (or waiting an hour).

Given the choice of spending $12 every few months for a "free replacement", versus buying an aftermarket capsule for about $12 (and changing it myself) that is guaranteed for a year (and the non-Volvo ones do actually last much longer), the latter is a lot cheaper. I always carry spares.

The directional signal lamp failure problems are usually the socket rather than the bulb. The sockets cannot withstand the lamp heat and fail. My S70 faithfully required a new one every year. This flaw has not been addressed 3 model years later. My S80 already has a replacement socket on back order, as the original failed within 6 months. GM and Ford, hardly pillars of quality, would have found a new socket supplier years ago. Incidentally, the sockets have always been replaced without any charge.