I'm a strong non-owning fan of the Varia, but......I hardly ever ride on the road, and hate gadgets that require charging, etc., etc., so I never quite get around to buying one.
That said, I do ride in (somewhat hokey looking) cat ears. I did it to protect my ears on long, searingly-fast downhills, but the side benefit that I've noticed is that I hear cars behind me a LOT better.
Cat-Ears is the leading manufacturer of aero-acoustically designed passive wind noise reduction products for serious cyclists. Tested and recommended by respected publications and professionals, Cat-Ears / AirStreamz are 100% Satisfaction Guaranteed and Made in the USA.
www.cat-ears.com
And, no charging!