minimum wiring required for 5902 alarm

Hey guys, I've been looking to add an alarm ever since one of my car got stolen. At first I was thinking of getting Viper 5902 with remote start and tilt sensor, but was quoted $1200 which I found to be quite a bit more then I'm willing to pay for -- and wasn't too keen on carrying 2 key fops. I've a 2008 Lexus IS350 and am thinking about only connecting the alarm and sensors for it to work for now (i.e. I don't want door locks or remote start, only the shock sensor, a tilt sensor, and motion sensor to set off the alarm siren). I think this will be a simpler installation that I can do relatively quick, and I might connect the other features if this is a great success :-) So, is there only a few connections, like power and such, that I need to connect to the brain and plug in the sensor and siren and it will work after arming? Thanks

You need to wire up Constant 12V, Ignition 12V, Ground, the Siren wire, and door trigger.  And of course the valet / LED components as well. 

Thanks; now I got more questions :-) All the connection will be at the H1 harness? I can find those wires in the car except the door trigger. Is this the (+) door trigger or the (-) door trigger? Is it the same as the DOORPIN in this post https://www.the12volt.com/installbay/forum_posts.asp~TID~103587 How can I test to see which wire is the door trigger and polarity? Almost forgot, I assume the 2-way remote will also work even with just these connections?

I also want to ask if anyone else knows that the door trigger is needed for the alarm to function or just so the alarm will sound when the door is opened?

If you don't want that stuff you are wasting your money getting a 5902, unless your just trying to look cool and don't actually care about your stuff getting jacked.

Well, it's always important to look cool As I said, I think the installer/dealers want a lot more than what I think it's fair, but that's OK, if that's what the market price is, that's what it is. I can do this myself easily if I got the wiring diagrams or schematics. Since I have neither, I want to start slow. The main concern for me at this point is to get the alarm and tilt sensor that will notify me. The car already come with an alarm that sounds when the car door is opened and an immobilizer. The only thing missing is when someone break the window and lifting the car, and also a 2-way pager notification that I want (the reason I picked a 5902).

Thanks i am an idiot, I connected the alarm today without the door trigger and works as expected (except the proximity sensor that goes off when armed, I'll try to adjust it tomorrow). The hardest part was getting the dash open, that take a good 6 hours (I should be able to get to it again in less than 15 minutes :-)