RS on 07 Saturn Ion

I'm planning on doing a remote start on 07 Ion soon. Car is 2 door, power lock's and saturns stupid theft content alarm. just wanting to get my duck in a row here.

First off, anyone have a diagram for an 07? I have found some for an 06, but I'm now sure if they're the same. If no one has info for 07, I'll carefully check all wires before making connections.   I know that I have to use an interface module. I plan on using PLXR unit.    I'm checking to make sure that that I'm understanding the lock system( as I've never done this type before). The diagrams say that they are a single wire. The charts tha I have found say  it's a grounding system. It's says to run lock wire from RS to car lock wire, then hook the unlock wire to the same wire, but through a 1k resister.       Also wondering on the tack hook up, andwhere that I can pull it from inside? Would rather not ppull it from under hood due to corrosion potential.

Any other things that I should look out for?

Thank's in Advance

Norm