A system and method for guiding placement of a vehicle service external fixture relative to a vehicle undergoing service or inspection. A vehicle service system support structure having at least one camera module is positioned at an initial location within a vehicle service area, and a location of the initial location within a vehicle reference frame is established from images of optical targets secured to the vehicle. The vehicle service system support structure is subsequently repositioned relative to the vehicle to a new position located outside of an external fixture placement region, while maintaining at least one of the observed optical targets within a field of view of the camera module. The new position of the vehicle service system support structure within said vehicle reference frame is determined from target images, and a placement location within the placement region for the external fixture is identified relative to the vehicle.