FM transmitter choices

Up to now I have been using an old version of the Griffin iTrip FM transmitter with my iPod in the car.
I bought the iTrip some years ago when I was in the US and FM transmitters were not permitted in Europe, yet. The iTrip worked reasonably well, but as soon as you were driving into an area where the chosen frequency was overlapping with a strong signal from a radio station, it had to be changed, first on the car radio and then on the iTrip. Quite a daring feat when driving on the highway or in a city.
I managed, but was frustrated by the low fidelity of the sound and how often I had to change the frequency to avoid the interferences and sudden jumps between iPod music and radio station chatter (in the end I simply stored FM 88.1, 88.2 and 88.3 on my car radio and jumped between these while driving, which was also easier to change on the iTrip without looking).

I recently checked how much it would cost to cable an AUX connection between my radio and maybe the glove compartment. But this was far too expensive, given that the full front panel of the car interior would need removal to reach the back of the radio.

So I decided to get a new and better FM transmitter.
Hard to find something, though.
When you read reviews you will see that due to FM transmitters never being as good as a cable connections, the overall satisfaction of users can only be mediocre. I eventually chose the Belkin TuneCast Auto. Like many other transmitters, it has a "clearscan" button which automatically finds the weakest frequency in the FM band and tunes on it. As a matter of course, you then still have to change to this frequency on your car radio, but this is a given with FM transmitters.
What I like about the TuneCast is that it also transmits the current song via RDS, i.e. you can see the name of the artist and the song title on the radio display. That's pretty neat and useful, as I have checked for song names more than once in the past.
And I must say that I was more than pleased with the TuneCast on my ride back to Belgium this afternoon.
The sound quality is way better than with my old iTrip which is due to more available space for the antenna versus the iTrip and of course due to the clearscan functionality which makes it much easier to find a suitable frequency.

What I do not like is that I cannot prevent the iPod from being charged all the time.
This is a function that I really do not need and you can tell me whatever you want about lithium-ion batteries, but they also suffer from being charged all the time or being charged when the device is only half empty.

So this is a major downside for all of the more sophisticated FM transmitters and I have to see how I will make sure that my iPod battery is not weakened too much by this feature.

A good thing is that I can use the TuneCast also with my iPhone. So should I need to charge it in the car, I can play the music from the phone instead of from the iPod.