I will not comment much regarding Washington, Oregon or Idaho as I am not a resident in those states. As for Utah, the law states that it is UNLAWFUL to carry in a vehicle UNLESS----
First, you are 18 years or older
Second, you are in Lawful possession of the vehicle OR have the permission for the party in lawful possession of the vehicle.
IF both of these conditions are met you can lawfully OC, CC, LOADED, or UNLOADED as LONG AS YOU ARE IN THE VEHICLE.
Upon leaving the vehicle, you must be OC'ing and the firearm MUST be UNLOADED if you are on a public road and not in a vehicle.
Utah defines "unloaded" as more that one single action required to fire the gun and no round in the chamber for a semi-auto or no round in the cylinder UNDER the hammer and the next one in rotation sequence for a revolver.
Utah does recognize the permits from ANY state or county, but you say you don't have a permit.
Regarding OREGON, when I have carried in a vehicle or for fuel stops in OREGON I have made sure I am OC'ing as they don't recognize my Utah or AZ permits. It is my understanding that as long as the firearm is visible in or on a vehicle you are good to go in Oregon except for those city's that have banned OC. My trips have be Motorcycle OC and I've not had any issues or problems. Your mileage may vary.
Idaho does recognize my UTAH permit so I've not worried about it either way.
As for Washington, my understanding is that to lawfully have a firearm in the vehicle that is not being carried in a manner compliant with the Federal Transport law (unloaded, and secured in a locked container, from a location where you may lawfully possess to another location where you may lawfully possess) YOU MUST HAVE A PERMIT EITHER FROM WASHINGTON OR A STATE THEY RECOGNIZE.