OE = Austria
FWIW, OE is like a country code assigned to Austria, much the same way as radio or TV station call letters in the US all start with K or W, and US registered airplanes have tail numbers which start with N.
2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg
And remember folks, Only You Can Prevent Hilliary.