I installed a F900 in my 05 tC last month. It's pretty easy provided you use a wiring harness. I bought my harness through Crutchfield. I don't remember the exact cost but it was +/- $10.00.
For tips on modifying the stock mounting bracket so the door will still close, check out
http://www.scionlife.com/forums/viewtop ... +placement
For info on locating your GPS antenna and, if applicable, Sat radio antenna, check out
http://www.scionlife.com/forums/viewtopic.php?t=173399
For info the wiring harness and mounting kit check out
Wiring Harness: http://www.crutchfi