I personally wouldn't do it, whether it offends others or not. I think it's morally wrong. I am NOT and have never been in the military (just a Navy brat), so this is my own personal civilian take on it.
I'm sure you wouldn't be the first to fly an emblem that (no offense) doesn't belong to you. But that just wouldn't be an option for me. I just have way too much respect for what our military does to even consider something like that.
Again, just my own non-military opinion. Not bashing, just saying what I think.
It's really not about what other people will think of it... would you really feel ok with that emblem on your car, knowing what it's supposed to represent?
I'm all about sharing the road with other drivers - as long as they use the part that's behind me.