1) plan.. plan.. and search the form.. many people have a celica
2) sure.. someone can break in to steal the change for booze. If your worried get an in-dash LCD
3) ahh probably
4) in-dash, mount somewhere, or build a custom dash
5) panel for the lcd? sure you can fiberglass
6) no.. 40 pin IDE only runs 3 feet max. You'll need a usb or i'd go with firewire to IDE. So the firewire cable is going to the front from the back.
7) search button can
8) see 7)