I have a 2005 Toyota Highlander. When I start it, it makes a noise like an empty drum scraping along the pavement.

This was my problem and solution today, on my 2006 Highlander, that had been driving in salted area for about 6 years of its 11 year life.. Brake / dust back shields now removed from the rear wheels (one side essentially had fallen off and making noise, the second was about 50% rusted away). All is perfectly quiet now.