The A and B connectors are standard ISO ones, which should fit 99.9% of today's stereos. AFAIK there's no standard for CD changer connections. The above diagram, or a Google search for "car stereo ISO connectors" will show a diagram of the relevant connections - the car you're fitting it to will most likely have the ISO plugs already, unless its an old car.
What is the "different vehicle" the stereo's going into?