Just a "heads up" for 2015 Excursion 33D owners.  I went through a shallow dip and heard a loud scraping noise.  It was a generator access panel/door located on the bottom of the generator.  It had come open, dragged on the pavement, and was bent out of shape.  I had the panel straightened and reinstalled by a Cummins/Onan dealer. After driving another 125 miles it fell open again.  A different Cummins/Onan dealer ordered and installed a new one.  It has stayed in place so far.