Ipod Adapter for Pioneer Car Stereo

Hi there experts and wannabe experts.

I just got a new Pioneer car deck with a USB iPod connecter. When I connect my iPod (which is 4-5 years old) an error message appears. According to the manual, my Ipod is too old. So the good people at Pioneer want me to buy what appears to me to be an external drive that I would basically transfer all of my music over to. The price is around $130. This seems ridiculous to me and I am thinking there must be some other kind of adapter out there. I'd rather get a new Ipod than that dumb Pioneer dealie. BUT, it seems kinda stupid because we have two older Ipods with tons of memory and they both work great.

Any ideas?

Much appreciated!
-Ln