I have degrees in Central European History and German, so I think I can take a stab at this. Luftwaffe is still used to this day for the Federal Republic's air force; I have friends who served in the Luftwaffe just a few years ago. Yes, this word has negative connotations, but I'm guessing that most Americans won't even know what it means. The few that do will recognize it from the History Channel and remember the link to WWII. So would I put it on my car? No. But that's me. I have a real German plate from when I lived there, but my state requires a front plate and I don't want to deal with that situation...
2002 X5 3.0i/man.*
2013 X1 xDrive35i Alpinweiß/Schwarz/M Sport/Dinan Stage 2