I honestly think they don't notice much else when they're flying along in a group like that. I've seen guys blow past me in a pack, and then I've seen the same guys waving and saying hello to me in the mornings when they're coasting alone.
Where I live, there are a lot of pros who train so I'm getting used to it. Plus, I can always hear that rumble-hum when they're approaching.
(KSH... Pirahna Packs, that's a good one.)

On the good side, they give me a VERY nice view to look at as they speed away!

Joy