Best buy has a Sony MP3 unit thats on sale this week for $99. Usually cost $169.
I had one similar to that and it was OK until it was stolen.
I then bought a Panansonic 1300 from Cardomain for $125 and it was a great purchase.
They include a harnness and a an adapter fpr FREE. These 2 items will cost you $30-40 at the store.
I did the installation myself abd its really easy. I wouldn't never pay ~$50 for instalation again...its a rip-off.
From experience of the 2, the Panasonic is definately better.
First, it plays WMA file as well as MP3.
Second, it read the disc better....I had dics that ths Sony would not read the the Pana would.
Third, I didn't even realize this afterward but the Pana is much better if you ever want to add an AMP(you probably won't but I didn't either at first).
The Pana has 2 sets of pre-amp outputs so you can easily connect a 4 channel AMP as oppose to getting adapter. Also the pre-amp outputs are rated at 2.5 volts as oppose to the Sony 2.0(higher voltage, better signal to your AMP.
The Pana 1300 is the best MP3 unit for under $150.