Just auto start

the big problem is the transponder key , if ya bypass the rest is simple

If you still want to use your factory remotes and with this vehicle,you need to sacrifice a sentry key which will go with a transponder bypass module.next you need to find the factory alarm disarm wire.This is lots of work. You can use your factory keyless and use your 2 way for alarm/autostart only.You can save lots of time by not using keyless on your aftermarket alarm. I could suggest another thing if 2way is not a must,just install a remote autostart which can be controlled by your factory remotes, just by pressing lock button three times. The auto start has to have a programmable feature which could do this.

Get a Python 581XP. Two-way transponder system. Get a 455J to control the factory alarm / doorlocks. Get a 555C for the transponder bypass. One remote, 2-way remote with 1/4 mile range. You can hook up an output from the remote start to pulse the memory seat wire in the door everytime you Unlock the doors by remote. Here's how it would work for the primary driver. One 2-way remote, arm and disarms factory alarm, locks and unlocks doors, puts seat/settings into memory position 1. For a secondary driver, they would have to continue to carry the remote from the factory and use it for locking/unlocking the doors if you only want to hit one button to get in. Another option would be to hit unlock, and then hold down aux. for a couple seconds to set the memory position in the jeep to #2. Typical costs installed: $400 - 2-way remote start $50 - transponder bypass $50 - doorlock interface $100 - extra 2-way remote for spouse. unit only comes with one remote $50 - extra labor to make factory settings work from aftermarket remote. It involves running wires into the drivers door to tap into the memory switch buttons.

Jworm I like your Idea!  Could you give some more details and the best place to purchase the DEI supplies.

JEEP / GRAND CHEROKEE / 1999 / Remote Start 12volts      red & pink/black        +       ignition harness Starter      yellow        +       ignition harness                 Ignition      dk. blue        +       ignition harness               Accessory      RED / black        +       ignition harness Second Accessory      BLACK/ orange        +       ignition harness        Power Lock      - see below Power Unlock       - see below Can use DEI part number 455J door lock interface control module. This will control door lock, unlock, arm, disarm, dome light supervision and more. Parking Lights+      use (-) lights               Parking Lights-      dk. blue/pink              steering column Notes: The dk. blue/pink will flash the hazard lights. They will flash even with a latch input to the wire. The parking lights can be activated by using a 1300 ohm resistor to ground on the yellow headlight wire. There is a rest resistance on the wire, so MUST use a relay to isolate away from the switch. *** I have an easier way of doing this that is a straight negative trigger. I think there is a tech tip on this site that has pictures. I'll dig it up later***      Tachometer                     Notes: The 4.7L motor has a separate coil for each cylinder. Go to any coil and use any wire that is NOT dk. GREEN/ orange. On the 4.0L motor use any of the tan/stripe wires at the coil pack, or go to one of the fuel injector and use the wire that is NOT dk. GREEN/ orange. Brake Wire      WHITE/ tan        +       drivers kick panel   Immobilizer Bypass Module:     Required: Yes     Type: Sentry Key     Part #: 555C or 555U Notes: Only vehicles with gray keys have the immobilizer.        I have done a ton of remote starts on 99+ Grand Cherokees. Easy vehicles for me to do. I have never hooked into the memory seats on a customers vehicles, but that's because nobody has ever cared enough about it to be willing to pay the extra money for it to be done. Its simple to find the right wires at the memory seat buttons if you know how to use a multimeter. Problem is, its a pain in the butt to run wires into the doors due to the molex plugs in the door boot, and you will need to run 2 wires into the door to accomplish what you want done. I recommend downloading and reading the install manuals at www.directed.com before deciding to do this on your own. If you can't find them, drop me a PM and I could email them to you.