In GT5 there was a save feature for endurance races that lets you save the progress and continue later, This is a lifesaver for endurance races.To be honest, I don't really like leaving an AI to do the driving for me. But it's the only way I can complete the 24-hour races. None of my friends play racing games, so they can't help me out there. And I've never liked leaving my consoles on for several days at a time because, as far as I am aware, doing so can actually damage them (by overheating). So B-Spec is realistically the only way I can complete them.