Ummm.
My 87 has keyless entry. But it was on it when I got it. (Also you can use keys and use door lock switchs)
Consists of module & remotes. But has several relays off the module, one in parallel with locking switch in drivers door.
You press to lock, locks both doors and sets alarm.
Press unlock, unlocks both doors and negates the alarm.
I recently bought a $13.47 alarm from Chinwa, delivered to home all inclusive.
This one has configurable function/remotes. It could (maybe) do the following.
1. Unlock doors (negates alarm)
2. Locks doors. (Sets alarm)
3. Open / release rear hatch (glass)
4. Wind down both windows.
AND start the car.
But it must wait as the car has no coolant in it.