installing trailer brake controller

[tomb57]

I recently bought a 2010 rx350 with the tow package.  I have installlled the hitch, and the flat 4 trailer wiring at the back factory plug.  I now have to install the trailer brake controller on the dash and wire it in.  Does anybody have any tips on attaching it to the dash, where to go through the  firewall, and any other tidbits.  Thanks ahead of time.  Oh, also, is there a  factory plug and wireing up by the dash, like at the back?