At the tire center in Portland, getting the right-front rim replaced. The previous owner of the van, an electrical and plumbing company, regularly drove the van with several thousand pounds of tools and parts in the back. Apparently they also bumped it up on the curb a lot too. With this wheel replaced, the rattling of the van was reduced another 80% at least. We no longer have to take it up to 80mph to get it running smooth.