For you folks that have a Varia, will it pick up another cyclist coming up from behind or does it need something bigger? I ride 15 to 25 miles 3 or 4 times a week for fitness. Those rides are mostly road. There, 95% of the time I'm fine with a mirror although that 5% or so of the time I miss a car coming from so the Varia might help a bit there. However my wife and I ride a near by rail trail and she likes what I call "a smell the roses pace", aka, "a gawk and talk pace" of about 8 to 10 MPH.. We frequently ride side by side until I see a cyclist(s) coming up from behind (or up ahead) and I move over until they pass. After we get 5 miles or so out from the starting point, the crowds thin out and yep, I get less attentive to the mirror and start missing riders coming up from behind. That's where I'd like some sort of audible warning.