I have that option on my 99, your key will have 2 buttons (one for locks, one for rear trunk). Its effing amazzzing, get it, or get aftermarket (with remote start )
I think what Tool Pants is getting at is if you can unlock the Passenger side Door with a key, you do not have the M535 Option (remote controlled Alarm System - USA).
IIRC, the Passenger side Lock Tumbler is eliminated on cars with the M535 Option, at least it is in my car...
You don't have an alarm/keyless entry option..to install a porsche factory alarm requires that the entire car be rewired which will cost you thousands of dollars..best to go aftermarket..I have seen decent DEI systems out there for this car.