Didn't flap around at all even at 70+ mph.just doesn't seem to lay flat/compress like on the jk. The front hard leading edge is what is in view the entire time in the mirror, don't see how a strap would fix what I'm seeing.No ,put a velcro strap around the fabric to keep it tight and not flapping around. I got 2 straps at Amazon for 6 bucks.
These fit perfectly around the folded top and greatly improve visibility. I never noticed any flapping, but maybe the aerodynamics are different on a 2dr.
VELCRO Brand - All Purpose Straps -... https://www.amazon.com/dp/B00575600W?ref=yo_pop_ma_swf