Park the car in the sun. Roll up the windows. Place the fruits or vegetables on oven racks, window screens (if you do this, place a single layer of cheesecloth over the screen first), or anything else that can be used to act as a rack and allow air to circulate. Place the trays in the vehicle so that the air will circulate well around them, close the vehicle up and check back every 4-6 hours until the fruits and veggies are dehydrated to where you want them. I will advise not to dehydrate onions, peppers, or other strong smelling foods like this. The stink will last awhile with those items.
The higher the temperature is outside, the faster things will dry out. I don't think I'd do meat like this.
The higher the temperature is outside, the faster things will dry out. I don't think I'd do meat like this.