1997 Civic RS w/ Defrost

Here is the deal, I installed the RS (Autopage 610rs) last Xmas for my wife. Everything is in and works fine, but she asked me about the rear defrost last week. In all my searching I have yet to find a definitive answer on how to properly set-up the RS to turn on the rear defrost when the car is started. Option 1: use 3rd ignition wire to relay to defrost. This would require a switch so as not to activate rear defrost in summer. Option 2: use the channel 2 (trunk pop) output to relay to defrost. The main problems I have encountered is the only info I can find for location of this wire says N/A and the it is on a timed switch. Can I do this in this car and what would be the best way to wire the relay? Thanks.

Use your CH.2 output with a latching relay, this way you can turn it on and off from your remote. Test the output of your defrost switch. The link to the diagram shows a (+) output, you may need to add an extra relay if you need a (-) output. Latched relay setupASE Certified