I also lost one of the Freightliner logo center caps. Went to a FTL dealer (truck) and purchased a pair of plain chrome center caps (very inexpensive but also rather flimsy) and have those on now. Be sure to take the remaining cap with you as there are several sizes available. Plan to replace the logo version next time I am at Gaffney. Hope this helps.
2007 Itasca Meridian 36G