Is there any way to save your progress in the Endurance Races?

I've reached the final series in GT5, the Endurance Series, which features races that range from 4 hours to 24 hours in length. As I do not have 24 hours of free time for gaming, nor do I relish the thought of a power outage causing me to lose 22 hours of racing, I was wondering if there is any way to save your progress in these races.

I've started a couple of them and there does not appear to be any relevant options on the pause menu.

Solution 1:

Go into the pit. There will be a "suspend" option. Then you can freely exit the game via the PS button.
BUT you cannot do any other activities until you are finished with the endurance race, which GT5 will prompt you about next time you start up the game.