I've sent a pm and would also like to get a step by step for this, E-mail in pm. Great job man.
i know this is almost a dead thread, but i've installed a system for a customer called the st800 by auto innovatio.
it sounds to me like that would work for ya. i love the system.. once i decide to do power locks on my truck, i'll end up installing one in it.
look up digital guard dog...
Parts Collected [98.5%]
Installation & Fabrication [98%]
Total Completion Level [96.9 %]
ah dude PM me. i'll get you some pics of what we did for him. i ended up making a place for the button to sit and look OEM. rather than sit on the steering wheel where it can't be seen.
EDIT: and ironically enough, he has a 2004 rsx as well