How to install wind wings

[Hioridge]

My wife bought me a pair of etched wind wings to replace the plain ones on my 1930 Phaeton. She said they weren't pretty enough.
Which way should the etched side of the glass be on? Facing the front or facing the back?
I'm guessing the back so as to keep the bugs out of the etching, but I would like to be sure and do it right (the first time).
Thanks.