It's difficult for people to test this. Most of us got rid of our PS2s when we bought our PS3s. Those that didn't probably only have one copy of GT4. So you're looking for a rare type.. one that not only kept the PS2, but also has a second copy of GT4 and a second TV to play it on. Probably not many of us around here that fit into that category.
Me, I'm in the second group. I still have my PS2 for the time being, but I have only one copy of GT4, and only one television.