My Volvo V50 has no such connector :´(

How exactly does it not work? Does it go like "no music found", "no device found", "incompatible device" or is there any blue smoke?

Correct me if I am wrong, but when you connect a N900 to a PC for the first time in mass storage mode, it will map up TWO removable disks, right? One for the SD card, and one for the internal memory card. Maybe your Volvo opens the wrong one, or maybe it gets confused.

Edit: too late. What he said.