I bought this FM Transmitter for my iPhone 4S, because I did not want to rebuild my very big standard radio. It worked really well initially. Search people Simple unused frequency, connect, running. With very slight cracking noises you have now and anleben but. However it has been shown to me that in many areas the noise is worse or you drive also someday through areas where the frequency is evidence. The search for a new frequency during driving is then a bit annoying, but works well.
All in all, I'm so happy for my needs. In most areas you can hear almost without restriction. However, it is not nearly comparable to the quality of a remote AUX or Bluetooth.