"Great unit, read my experiences with the FM Transmitter"3.5 starson by chooch331
Pros: Perfect solution for somebody with a bluetooth-only music phone who wants to be hands-free while driving and listen to their tunes through their car's speakers and their car has no AUX jack or bluetooth built-in.
Cons: FM Transmitter is tempermental -- but can be fixed
Summary: I cannot wear conventional bluetooth headphones because of my ears and the fact that most headsets have earbuds that push wax back into my ears. I like to carry only one device for phone and music and want to have audio through the car speakers, if possible. This product fits the bill entirely.
The only problem is the FM transmitter. Plantromics gives you a choice of five FM frequencies in the 88.3 to 89.7 or so range. WHY Plantronics did that is puzzling because those frequencies are not in the lower, more quieter end of the FM broadcast spectrum. I live in a major metropolitan area and all five frequencies are either the carrier for an FM broadcast station or the strong sidebands of those stations.
Since this thing uses any FM radio, I tried my home FM radio and could ONLY get static-free music if I placed the K100 directly on the radio. My heart sank as I couldn't see this working in the car and I was right. I then discovered that the unit would work if plugged into the USB charger port and this cleared up the static immediately!
To make a long post really short, I got the unit to work perfectly by keeping the supplied USB charging cord connected to the K100, clipped the K100 to my sunvisor, and the coiled the remaining USB cord length around the rear-view mirror. Now, surrounding broadcast station noise isn't a problem and it works GREAT! I don't know if the cord is acting as an antenna element or antenna counterpoise (reflector) but it did the trick.