There's an element of canbus data that was forced to be generic by international standards - eg: data from ECU. This can be read fairly easily by aftermarket devices via obd port.
Other interior functions like climate control,lights,horns and anything deemed lower priority than essential for engine/safety is on a lin-bus.
It's easier to trick the lin-bus into doing what you want, and reverse engineer the signals needed. Most of the lin-bus stuff would be fairly similar on Volvo's of the same era.
Feel free to pm me/post the products your looking at and I'll confirm if they will work for you
