@YourGardenShow: The car windows actually do work! It gets hot in there fast when the sun is shining on a car with the windows rolled up...
When I dry tomatoes in my dehydrators I set the temp at 135 degrees. If you can set your oven that low, it should work as well. They take awhile to dry if I cut the tomatoes in half, but quicker if I slice them into 1/4 inch slices. If they get crisp, let them sit for a while in open air and they get leathery again pretty fast.
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