I have a '01 V70 XC. My dealer warned me not to get the Volvo trailer hitch since it cost $800 and was not compatible with US receiver accessories. Also, Volvo didn't have a wiring kit even though the car has a plug with all of the right connections in the spare tire compartment.
I went to U-Haul and got a Class II hitch (300# tongue load and 3,500# gross weight) with a 1.25" receiver. It is great. It is U-Haul model 36297 and costs $115. It only took U-Haul 30 minutes to install so it was a good fit. It is black and the receiver is under the bumper and forward so it isn't very noticeable.
The U-Haul receiver is $19.95 and curves up so that it is positioned behind the bumper.
For wiring, I got a wiring kit from a trailer shop near by for $20. The kit has the black box that converts the brakes plus 2 signals to 2 signals so that it will be compatible with the standard 4 pin plugs. I wired it into the plug next to the spare tire. Then I ran it through a passage to the lower right tail light access door. It is completely out of site. When I need it, I just open the door and run it out under the tailgate door through the rubber gasket. The advantage of the kit is that it has black shrouds that cover the wires and a cap that snaps over the end that plugs into the trailer when it isn't being used.
I am very pleased with how it worked out. The best part is that it doesn't cause the bulb-out light to come on.