If GT6 shows up on PS4, and stays mostly at GT5's level of graphical prowess, this might be the first time we could see this as an option. PD tends to push graphics so far - witness the choppy framerate a full grid race can provide - that the only way they could get away with rendering twice the number of cars in GT5, like in the case of two-player split-screen, would be to cut the graphic detailing pretty heavily. We already can't use interior views in split-screen, and you can be sure that was a performance decision.