I was pulled over when i was riding in my friends 2nd gen toyota pickup when we had no doors, we did not get a ticket but were told we needed to put the doors back on
After some research it looks like in oregon you can run with no doors as long as you have a body tub... as in the way many jeeps have the floor sunken like 4in and you have to climb over a threshold to get in.
I know this law veries from state to state.