Be proud of what car you have as it is ...any W124 is a nice ride.
Putting a 500E badge on it opens yourself up for a ton of ridicule; especially when you get smoked on the road by someone who wants to tangle with a real 500E.
...or go badgeless and keep them guessing !!...but anyone who knows cars will know yours is not a 500E if you badge it like that.
The great thing is that this is America and you can do that if you wish.