I'm going to be installing my first head unit/navi and have a few questions before I tackle this project. I apologize as I'm a n00b when it to car audio, but I love to learn and have no problem tearing apart the dash. This is all for a '99 ES300.

Here's my parts list so far:

• Pioneer AVIC-D3
  Installation Instructions
  
• Pioneer CD-I200 (for iPod)
  
  
• Scosche LS2081B (Double-DIN dash kit)
• some wire harness

QUESTIONS:

1. I want to retain all the stock speakers, sub, amp if possible. How can I do this? I've been doing a lot of research and I've read that it can't be done and I've read that it can be done w/ a line level(?) or something like that. I would really appreciate some clarification here.
2. Where can I locate the Vehicle Speed Sensor (VSS)?
3. The wire harness I see for my car on eBay looks different than the one that Crutchfield recommends. Does it matter?
4. What else do I need?

Thanks in advance for any help. I wanna get this done ASAP and will post pics as soon as it's done! :cheers: