Perhaps when you closed the trunk, the aging lock did not fully engage. You could try giving the top of the truck above the lock a good wack with your hand. This may fully engage the latch and then you can unlock it.
If it works, then lubricate the lock mechanism.
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Today's photo: A famous arch in Utah near Moab.
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Today's featured photo: Hills, water, and cows in Scotland.
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Our trip was mid summer 2009.
We got a glimpse of the Firth of Forth bridge, but did not get a photo.
Here is someone else's photo:

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Today's photos: More hills and water.
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Today's Photo: Passenger train in Northern Scotland. We did not ride the train but I visited the station.
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abscate,
I finally understand your obsession with used motor oil.
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Today's photo: Doing laundry at a caravan (camper) park in Scotland. We always carried about 4 days of clothes on our extended trips and found a laundromat to wash clothes. It was hard to find self service laundromats in Scotland for some reason.
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That is great news!
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Today's photo: Great Salt Lake and clouds.
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