Volvo consistently switches parts around on cars in the middle of a MY (model year) so to help track down parts for specific cars, parts counters will often ask for a VIN or chassis number.
The VIN is easy – it’s found on a riveted plate on the driver’s side dash visible from the windshield. For example, here is my VIN: YV4992DZ9A2085134
The chassis number? Well, that’s easy too. It’s simply the last 6 digits of your VIN. In this case, my chassis number is 085134