Best Way To Play Mp3 Music On A 2004 Gs?

[GS430SE]

I have a 2004 GS430 (2nd generation; Mark Levinson audio system with integrated Gen01 Satnav).

I am in the UK.

What is the best way to play MP3 music through my system, without appreciable loss of quality (which I'd suffer if I used a cassette adapter, even a Sony one)?

Connecting to the FM aerial in the rear of the car? Or dismount the head unit from the dash (I've managed it once and guess I could manage it again) and make a more permanent connection?

I'd prefer a controller/adapter which will allow me to directly plug in a USB stick (pen drive) containing MP3 files, rather than have to use an ipod or similar.

This said, the added ability to plug in an ipod, Android or iphone would be a plus.

Recommendations needed, please!

[1990LS400]

I think I've read that adapters from http://www.vaistech.com/dev/home.php work on U.K. models but you should check for yourself. You might prefer a 3.5mm aux-in over a USB so that you can connect your Android phone: http://www.vaistech.com/dev/sl2u.php It is also possible to connect a Bluetooth receiver device to a 3.5mm aux-in to allow A2DP wireless streaming from your phone to your car radio.

Are Internet music streaming services like Pandora and Slacker still unavailable in the U.K.? The attached photo shows my phone streaming a Dido song from the free (in the U.S.) Pandora Internet service to a 3.5mm aux-in on my radio. I also have a number of complete music albums stored on my phone's micro-SD card.

[GS430SE]

Thanks 1990LS400! I'd already emailed VAIS TECH for info and am waiting for a reply from them,

I'm not into tech as much as you are; I don't have an Android though it is possible I may get one. I have lots of music recorded on mp3, and have an "old" 60Gb ipod.