I've used this Speaker phone with both my Motorola V3 and Sony Ericsson phones and it works nicely. It is much louder and much clearer then the speaker function on the V3. I had no issues hearing and understanding people when traveling in my Tacoma at freeway speeds with the windows up. In my Miata convertible I can also hear most people decently with the top up, but some soft spoken people were difficult to hear at freeway speeds over the road noise. I must add that my Miata is a fairly noisy car, in most cars you will not have any problems hearing. Most people I talked to on it did not notice they were on a speaker phone. I did not try any voice dialing fratures, but those are really functions of the phone and not this product.