Just came across this again - it's been posted - but thought it may be of use to others... As you can see, the antenna goes under the dash - in the center. I still think locating it at one of the squakers (front tweeters) is far easier, and maybe a better location (direct line of sight)...
Tweeter area works fine for me - see http://priuschat.com/forums/gen-iii...74-chinese-replacement-hus-5.html#post1136516. With SIRF iV chipset, the GPS fix is almost immediate.
I've seen this document before. Does anyone have any experience removing the dash? How much time? Any tricks? I wound up getting a model III (JBL system) I don't think the tweeter location is viable.
Frenchie is the only one I know who actually pulled the dash. Your other option (much easier - and I'm sure as good or better reception) is to run the antenna up either side, along the A pillar, then put the antenna on the front window (any corner would work fine) - easy and pretty unobtrusive...
That's a pretty sweet PDF, I wish I could find one for the Prius C since I'm looking to do the same upgrade!
The document kindly shared by @rrolff is a European accessory installation manual. Toyota hasn’t sold the Prius c or Aqua in Europe, so there is no direct equivalent for the Prius c; if there were, it would be on toyota-tech.eu. For the Prius c, you can find illustrated, step-by-step instructions for removing the radio receiver, upper instrument panel, etc., in the Repair Manual, available by subscription to techinfo.toyota.com. The text and illustrations for 2016 and earlier Prius c models are also on the ChiltonLibrary service, to which the Los Angeles and Orange County public libraries both sponsor access (from home, if you have a library card) for their patrons.
