I'm installing my new NAV unit in my 97 ES300 and would like to know how to locate my speed sensor cable. Is there an easy way to find it in the cabin of the car, or do I have to go through the firewall and find it in the engine area? Also, what's the easiest way to tap into the parking brake and the brake light? Any help or advice is greatly appreciated! I'll post some photos when all is complete.

Thanks!!