which model so you have?

the main harness on these has a wire that is white w/blue tracer. it is many times hooked to a momentary button mounted to the dash or whatever...that when pressed turns the remote start on or off.

if your system has one of these buttons(and its the black one with the black base),  and you use it frequently, there is an extremely small chance that  the spring is a little weak or some how the button is getting shorted. maybe a newly added tension to the harness like a recent repair under the dash or something.

OR.... that wire wether or not its hooked to a switch is getting shorted briefly and starting the car.

OR ....another scenario is a wore out button on your fob. take the battery out for about a week and see if the problem goes away. first try it with one fob, then the other.

and last thing i can think of...a power loss and restoration to the module with the hood closed can trigger a start too on some models. so maybe look an intermittient power connection