Michelle, there's an Airstream dealer nearby, Windish. It's on the service road on the north side of the 6th Ave Freeway just east of the Smith/Union Blvd. interchange. I'm not their biggest fan, but they did a good job replacing the rear panel on our Safari after they backed it into another trailer's tongue. Dakota Ridge is the best RV park on West Colfax near there and about the only one on the west side of Denver. Sorry to hear about your mishap and hope you can make it to Jackson Center to get things fixed.
If the Arvada police tell you you have no claim against them because of sovereign
immunity, they don't know the law. I guess your insurance company will handle it.