Sorry, i don't have the NW E507, i do have the NW-HD5 and the Bean and therefore some experience w/ Sonic Stage.
As far as importing non Atrac formats, all you have to do is click and drag them into your sonic stage library. Afterwhich you simply choose your transfer preferences from the options menu and Sonic Stage will convert them to Atrac or Mp3 as it uploads the music onto your player.
I personally own the Sony FM Transmitter b/c my Honda Acccord doesn't have a tape deck. It works as good as any I've seen/heard and it was less than $30. It doesn't charge the unit, but that shouldn't be a problem considering the battery life the NE E507 boasts. It powers itself via cigeratte lighter adapter. They still have them instock at Target.
http://www.target.com/gp/detail.html/sr=1-8/qid=1141329308/ref=sr_1_8/601-5655395-6653750?%5Fencoding=UTF8&asin=B000BDIREM
A word to the wise though, no FM Transmitter is going to produce great sound. If you have a tape deck in your car, I'd recommend a tape adapter or a new head unit for your car with an aux input.
Impressed with the new Sony NW E507 1GB MP3 player so far except for some questions which the instruction book did not cover. First, how can I program the player to play continuously without stopping after all the tracks in one album is played?--inconvenient to re-scroll or restart the player while driving, etc.Second, how does one go about importing MP3 or other non-Atrac formats to the SonicStage software to enable transfer to the player? Third, anyone with recommendation for a "good" FM transmitter for car stereos using the DC source from the cigarette lighter for use with non-iPod MP3 players. I found that the battery run transmitters are not worth the money.Thanks.

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