I picked up one of these:

http://cgi.ebay.com/4GB-1-5-Car-MP4-...item3a532e4bc6

$19.95 shipped, ton of 'em out there. I went for the
1.5" screen because I wanted compactness and
will not be watching anything, just music.

It's a combo FM transmitter and MP3 player with 4GB
built in memory. I was using a lashup of MP3 player
and cig-lighter modulator in the Caprice but that is
a mess of wire on the front seat. This puppy plugs
in and all done.

It will only accept 1.85GB of files (viz advertized
4GB) but that's tolerable, since I could plug in a SD
media card if I had more I cared to listen to.

Audio quality is fine (for a 'vert with a loudish exhaust).
Some FM static but it tunes across the whole band so
you can find a quiet spot.

Random play starts off not being all that random, see
some repeats froma "short list" initially but it gets
better as you FF it; probably the "random" generator
needs to get churned a bit, or something. Tolerable.

Remote control is needed to access Random/Repeat
and tuning. The FF / skip button on the player body
is handy by the shifter when plugged in.

I no longer care about finding a MP3 CD changer for
the trunk, which is good since there seem to be none
for the GM interface, near as I can tell. Plus this little
guy does not skip when I get airborne on the crappy
roads hereabouts.

I'm gonna pick up a couple more, one per car. And
maybe a SD card for long trips.

 

Why not buy an iSimple interface and an iPod? Sure price is an issue, but what you are doing seems like a lot of work. I spent a little over $100 getting the interface working, and the hardest part about playing music now is opening the glovebox to change playlists on the iPod.

Edit: I got the iPod for free due to a dead battery and since then have spent an additional $60-$90 upgrading/repairing it. It now has a longer-lasting battery, and 32GB flash memory. I use it while driving and hook it up to the garage sound system when I work on my car.

 

Work? I loaded up the MP3s and plugged it in.

I don't have an iPod. With the 4GB SD card I bought
yesterday, I'm into it for a big $31 altogether.

 

Having used the thing for a while, I have come to
dislike it. My main beef is that the "random" shuffle
is not random at all, it keeps looping through just
a few of the hundresd of .mp3s loaded.

I tried another model, same theme, and it has no
random at all.

So I'm back to the separate modulator and MP3
player wireball, in the Caprice.

 

I figured you would become dissatisfied with either the performance or reliability of the unit over time. For $31 that's still not a bad player. I'm still happy with my cars hardwired iPod integration.

 

if you're looking for an inexpensive, yet useful mp3 player, look at the sansa players. I love my Sansa express and you can usually find their click model for under $50. Some of the best budget players I've had the chance to play with (and own)