Anyone can OC in OR. Just be careful about Portland Metro, Salem, Astoria and Independence. They have a prohibition on LOADED OC.
When Oregon wrote their preemption, they allowed local government to restrict
unlicensed LOADED OC. Portland, Beverton, Salem and Astoria all have restrictions on loaded OC without a CHL.
Interesting thing happened a few days ago. A guy from WA has his OC sidearm confiscated while watching a parade in Astoria. The new article did not say if he had a WA CPL, but did say he did not have an OR CHL.
The way Astoria's law on loaded OC is written, it is possible, if he has a WA CPL, that he can beat this. Astoria's law does not require a license from OR, it only requires a license from "lawful authority"????
Anyway, yes, you can loaded OC without a license anywhere in OR, including in your vehicle, except those places listed above (and maybe a couple others, check first)
www.opencarry.org has an Oregon forum, first sticky has a quick reference card (.pdf) to OR OC rules. about post #20
OR will issue a CHL to neighbor states that gets rid of all these silly local restrictions. Sheriff Palmer in Grant county is very 2A favorable and will make it easy for you to get a OR CHL if you want (I noticed you live in CA)