I got the same for 4.99 at a camper supply store (the type that sale RVs and traval trailers). Install is easy - basically you just screw them to the door panel where you want them.

These come in black, beige, olive and white. They do lack the little foam pad in the base the cup sits on that the offical Volvo part has, however a napkin does the job fine. I don't know if they can handle a big gulp (we don't have them here) but it holds a Wendy's Biggie or kid's sized drink just fine with 2 adjustable arms that hug the cup.