Maybe, it sounds good! But, everytime I see flow vis applied to the cars (I watch all fp runs) I always look at the patterns and it never ceases to amaze me how little effect even big wings seem to have. You cannot make air bend around corners, deflect a bit is the most that you can hope for it seems. I don’t think the mirror can bend the air down this massively. It certainly seems though that Ferrari did aim the mirror to do just that. The top shots comparing the 2017 to the 2018 car are very clear in that respect.
Now, and this is really true,
I am a RedBull fan (Max really) and last year when they introduced the super low drag car I was looking at the detailing and thinking about which drag inducing element remained and the mirrors seemed one of those things and I thought up the exact same solution Ferrari made here. But If I can think it up then I guess Redbull and all other teams must have looked I;to this and at least tested a windtunnel version?
So what is this mirror, viable or just a gimmick an amateur thinks of, or both or something in between.