I'm not sure that having the 12V outlets on all the time would be a good idea. My husband has set his XM Roady to turn itself off after an hour, because his Jetta doesn't turn off the power to its "cigarette lighter" and I think you can drain the battery by leaving the Roady on all the time. My Corolla, on the other hand, shuts off when I turn off the car, so the Roady doesn't drain the battery at all.