I once planed to do a similar project for my vibe. But after considerable research, I dropped the project. Because besides the main alarm system, I still need to buy sensors, modules, backup battery, etc. to make the alarm system more practical. And if I made a mistake during the project and can not figure it out, it will leave the car in an undriveable situation. At the end, I get used to not leaving anything valuable in the car. Here in south Florida, for a lower-mid range car (defined by Autockeck) like the vibe (not other Civics) without much modification, I don’t have much worry about it being stolen. Anyway here’s one of the best installation guide I found during my research, from trailvoy with a lot of pictures.
http://forums.trailvoy.com/showthread.php?t=65742And for installation videos, you can go to Youtube and search for Motorz channel. Hope these will help and please keep us updated if you plan to carry on this DIY project.