Crazy story today.
Had my Rx-8. Drove it about 10 miles to go see a movie with family. I stopped my car and the alarm starts blaring. Sirens. woooa woooa wooa weeeeooo wweeeeooo weeeooo. I frantically started smashing buttons on my keys to make it stop and it did. Went and saw the movie got back, opened the door that same alarm went off, but I was able to just stop it and drive away. I then proceed to drive to an outlet mall to shop. I finish shopping and then come back to put stuff in the car, I opened the door and nothing happened. Phew. But my car wouldn't start...... So I'm thinking huh? I'm inside the car. I open the door. The alarm goes off again. Confused as ever, I sit there and want to die. Car magically started. I get it back home and try to start it...... no start.

I bought my rx-8 2006 60k miles. And found that it came with an Excalibur alarm system. (Omega) ID: AL-xx60-edpb . I disconnected all the wires to the box for it that was under the dash, and it still won't start.
Really got me frustrated for only having it for like a week..... Anybody savvy with alarms know how to remove this thing? Almost 100% sure it's preventing my car from starting.

 

I don't know anything about alarms, but there's a chance the alarm is a symptom, not the problem. Check that the rest of your electrical system is ok. Battery, battery terminals, grounds, that kind of thing. Alarm could be getting reset by fluctuations in supplied power.

Or it could have been installed poorly. Anyway, these cars come with built-in alarms from the factory, perhaps what's going off.