I'm in Central Oregon and I believe they require an actual home address when you buy/register a car now. When I bought my car, they asked me to give them a cable or phone bill with my name and address on it as proof of residence in Oregon. Another reason is there is no sales tax up here, so apparently people were coming up here and buying cars tax-free and then taking them out of state. So they took steps to try and prevent that.

 

I know when I lived there in the 80's all you needed was a PO Box addy or better.

Not very hard to get a street addy - all you need to do is know someone that has a house and say they are your roommate. Have other folks do it on timeshare address'. Have a friend that has a timeshare at Bandon Dunes and he has his cars registered in Oregon using that address.

California is probably a lot more strict in enforcing out of state registrations. I drove in Arizona for 6 years before I changed - never even asked once about it.

 

Yep, there was a possibility that I was going to move to Colorado from Oregon awhile back, but no way in hell was I going to put my car back to stock just so I could register it there, so I was going to do exactly what you're talking about, claim a buddy's place as my residence so I could keep the OR registration while living in CO.