Sell car before registration?

Pretty sure I know the answer, but thought I would ask just in case.

I bought a car off lease a few months ago, and because of travel and me being lazy, I haven’t had a chance to register it yet, it was already registered in Texas while in lease.

I am now looking to trade the car in to a dealer in Seattle. Do I have to register the car before trading it in? Or can dealer in Seattle take care of it?

Is the title a new title or the one the bank sent you. If from the bank that might be a released title and most companies will not touch it. Especially Dealers

The one from the bank

Anything can be handled with a power of attorney. Dealer in SEA should take care of it.

I am looking at the title and power of attorney that Ally sent. Since I haven’t signed the title, there is nothing in the paperwork that states my name, even the power of attorney isn’t directed specifically to me. Which makes me feel like dealership shouldn’t have a problem with this.

But does this mean that if anyone stole the paperwork they can register the car in their name?