If you use separate PCs for visual, GSX vehicles won't work across them. The only way to have a continuous view, is to use a single PC, possibly with more than 1 video card, to drive all visuals.
This won't be changed, since synchronizing across a network all GSX vehicles with all their animations, for all frames, would put too much strain over the network, resulting in a lot of objects stuttering, which would defeat the purpose of using multiple PCs for visuals.