1988 MBZ 560SL factory alarm disarm

This is a bit long winded, but I wanted to be as detailed as possible. I recently installed a Sidewinder 6500ESP into my wife's 1988 MBZ 560SL convertible. I'm having a problem with the factory alarm intermittently going off. When I first installed the alarm without tying into the factory alarm disarm wire, this caused the factory horn to honk briefly after disarming the 6500. I assumed that this was the factory alarm going off, but then being shut off when the doors were unlocked. DEI tech support recommended tying the 6500's unlock output to the factory alarm disarm, which I found to be a green wire in the driver's side door boot. This cured the factory horn honk upon disarming, but the factory alarm would still go off when the 6500 was triggered. DEI tech support then recommended me tying the light GREEN/ black wire (factory disarm output) of the 6500 to the factory alarm disarm wire. The factory alarm no longer triggers when the 6500 is triggered, but for some reason the factory alarm intermitteltly goes off a few seconds once the 6500 is disarmed and the car is started and driven. At that point, the factory alarm shuts off after the ignition is shut off. Anyone have any ideas? I made most of my connections at the factory alarm unit behind the glove box. DEI tech support didn't recommend permanently grounding the factory alarm disarm wire. Can the 2 plugs be unplugged from the factory alarm and not cause any problems? Thanks in advance.Friends Don't Let Friends Bump Stock.

Upon further troubleshooting, here's what I found out. When the car is started and the 6500 locks the doors via the ignition controlled door locks. Approximately 5 seconds later, if the brake pedal is pushed, the factory alarm goes off. This has nothing to do with arming/disarming the 6500. The factory alarm is being armed when the 6500 locks the doors upon ignition, and is being triggered by the current draw of the brake lights. Is the next step to tie the door lock wire of the 6500 to the factory disarm wire, so that the factory alarm is disarmed after the doors are locked?Friends Don't Let Friends Bump Stock.