What every best has:
The problem, many of them say, is in the technology; the Jupiter Jack doesn't have its own microphone, but relies on your mobile phone mike and picks up the calls through your car's FM signal. Since FM radio signals can vary from mile to mile, the Jupiter Jack's reception will go in and out, which can be annoying and even distracting for many drivers.
We found a handful of well-done hands-on tests. On Honest-Infomercial-Reviews.com, editor Theresa Kruger posts a TV news report made by Greensboro, N.C., consumer reporter Melissa Painter, who takes a local construction contractor out for a road test of the Jupiter Jack. Throughout the ride he makes several phone calls that result in -- as he puts it -- static with a little bit of voice mixed in. Turning up the volume and even moving the cell phone to different areas of the dashboard doesn't help reception at all.
StarReviews.com gives the Jupiter Jack a good review after demonstrating an in-car test where you can hear the call recipient clearly. However, the test is conducted in a parked car and the vehicle never moves, so the product is never actually tested on the road. On the other hand, all other hands-on tests we encountered as well as the overwhelming majority of Amazon.com users give the Jupiter Jack bad reviews, saying that phone reception is poor or nonexistent.
In a two-for-one deal on the product website, you can get two Jupiter Jacks for $10, but you have to pay a shipping and handling charge of $6.99 for each Jupiter Jack. Several adapters are included to accommodate different types of phones -- although a few reviewers say that none of the adapters fit their phones properly. It's worth noting that, when this product first hit the market a few years ago, Bluetooth wireless cell-phone systems cost considerably more than they do now, so many Jupiter Jacks were probably sold on the strength of its cheap price tag. You might want to check out our report on Bluetooth headsets, which start at about $30.