I recently purchased an Ultimate UFM31 FM transmitter which has a built-in media player to play mp3s directly from SD and USB memory. I was dissapointed that I cannot easily jump from MP3 folder to folder.

Can anyone suggest a good FM transmitter that I can use in-car with the ability to read MP3s from USB and jump from folder to folder?

I am only considering FM transmitters at this time as my car ('04 mazda 6i) doesn't have an aux-in or any type of ipod hookup, and this is the easiest/cheapest way to get mp3s in my car.