this post may be long but we're trying to gather some info from folks that may have experienced something similar.

i use a 16gb micro-sd card strapped to a usb card reader and plugged into the vehicle's receptacle. it contains a few thousand mp3 files in just under 300 folders. when it works, it works fine. i use that as a backdrop to avoid the "help" with the obvious.

i can run with this setup without unplugging the usb reader for weeks, even months then all of a sudden, poof! after a crank, the usb is no longer recognized and nothing plays. in most cases, once the problem presents, removing then reinserting the usb reader into the receptacle, causes the audio device to shut off or display 2 folders with no text. once it fails in that manner, if i take the reader to a windows pc, it's defunct. this behavior has been seen with different devices in different vehicles. i will then remove the sd card and try another usb reader and in most cases, we're back. note that i've also used different and the same data on a different micro sd card, same behavior.

so a new usb reader that won't play in my ls may very play fine in a '13 es another 13 ls or my friend's 2010 rx. i ran with this in my friend's rx for a few hours while xmas shopping and after a several starts and stops, it just stopped playing. mind u, she runs a premium sound system while i roll with ml. in both vehicles, once it stops playing, the audio system turns off.

my guess is that we have an voltage spike or current overload condition that blows a component in the usb reader. in all cases, the micro sd card is never damaged, just the usb adapter.

any thoughts or similar experiences would be appreciated. and yes, my local dealer is very on top of this but as u can read, it's complex.