perfectly adequate for in-car use

The FM transmitter is well made right for its price - by design unmistakably oriented iPhone. Of course, on closer inspection already noticeable differences in quality. On closer inspection, dominates the cover plate with the screen on one side a little further over the edge than on the other (at least in my transmitter). This is due to the switches for frequency tuning, which are mounted under the completely smooth cover plate. And when the backlight is turned on, is also in some places the gap between the cover plate and the 'aluminum edge' (which, however, in reality, is made of plastic) involuntarily lighted. The backlight is activated briefly but only at power and during the frequency setting.
But hey: the transmitter comes from a completely different price league than the iPhone. And since one must also be able to take somewhere small drawbacks in buying.
Finally, yes it is primarily also important that this part fulfilled its purpose: namely, live streams and mp3s transferred from the mobile phone to the car radio. And that does it - even in very decent quality. The operation of the transmitter is clear and self-explanatory: on / off, tuning up, tuning down - so really simple and easy to use. Its range is approximately 5 meters. This radius even puts it away strong stations, the regional radio on the same frequency. However, it has also shown that different frequency transmitter (with more power), the sparks in the immediate vicinity on the same frequency, in turn, completely superimposed on the signal of this here (eg at traffic lights, in traffic or when overtaking on the freeway). But then one can quickly change the frequency when one takes too long, or meet at rush hour coming back to the same Pappenheimer with competing programs.
A bad noise, as described in other reviews, I can not confirm. There are of course the normal, light frequency noise of the car radio in 'absolute silence in the program'. Once music is playing, but that is no longer perceptible.
And when the phone the headphone socket disabled because nothing is played, it is perfectly normal that then drowned the much louder noise of tuning the car radio. So hear everything as in a normal radio (also that the signal eventually switches to mono at a greater distance). In the car but that should not be the case - which I can not judge how much the car roof or the body impedes the reception because the antenna is embedded in my in the disc.
The service life of this little device I can not yet judge so far, of course. But for the first impression I am very satisfied, especially as the set frequency is retained even when switched off the transmitter. So for me, right here, the price-performance ratio completely!

ADDENDUM:
Meanwhile, I was able to test the part extensively. Does the battery, according to the first store, with me at the moment two hours. This is certainly a little rise. Nevertheless, that would be really very little if one has to rely solely on the battery charge. In the car, the micro-USB charging cable (that is with me on the phone anyway at the start) but connected quickly. The shop also functions during operation. However, while charging an ugly, slight humming occur once the battery is full again.
For signal transmission is also still to be noted that the transmitter is not insensitive to interference from outside. Every now and then it may be time to come spatters. But that is very rare and seem to be dependent on the environment. Even the Frequnzsuchen of D-network phones interspersed now and then unsightly into the signal.
And I could observe something quite curious: There are actually transmission fluctuations which make the car radio at times back and-forth between stereo and mono. This is quite strange that so neither the distance between transmitter and receiver in the car changes, even arise any obstacles and disappear, which could interfere with the transmission. However, that's far too rarely occurred and only in mountainous regions.
In spite of everything, for me, the positive impression remains, and therefore also the four stars in this review.