Yes, very much so. And it will track multiple cars presuming they are not hidden completely behind one another. It reaches out about 500' or about one city block. On the highway, it gives you about a 6-7 second warning of an approaching car at 60mph or so. In the city, it's much longer than that because cars are moving slower.

I was prepared to think it was kind of an gimmicky thing, but I'm really starting to like it a lot. I haven't had it give me a false negative yet (i.e. not identifying a following car when there was one) and don't think it will. I have gotten a couple of false positives (telling me there was a car there when there wasn't) but that seemed to happen on turns when there was a large metal sign down range or a car in part of the intersection as I turn through it. I don't get false positives when I'm riding down the road.

The tail light is pretty much unimpressive at 16 lumens. The idea that it starts and blinks as a car approaches is nice, but it really needs to be more in the 70-100 lumen range IMHO. I ride with some serious tail lights (high bright ones) that cause driver behavior to change. This light does not induce that behavior and I would not recommend it as the only tail light for a night ride. I also wish Garmin would add the choice to completely turn the tail light off but leave the radar on.

So I think it's an impressive product. I definitely appreciate the cue to look in the mirror or to turn around and look. I do find that I miss it if I don't have it on the bike.

J.