Well like may of the D3 owners out there, I recently connected my iPhone 3g to my D3 and couldn't charge it. But after doing some research, I found that help is on the way and not from Pioneer.
Check out this link to endaget for adapters that will be coming soon. If what I read is true, they should work with any charger or Ipod connnector out there, including the ones for the AVIC units.