If you forget to lock the doors of course they will be unlocked when you return, that is if the car is still there.

he 'feature' that I think you are getting confused with is if you lock your doors then accidentally press the unlock on your key fob, as long as a door is not opened the doors will auto lock after a short while.

So, as the old adverts used to say "Lock it or Lose it"

 

Thank you for the reply but l assumed that once the key fob is out of the car and no longer in sight of its electronics the doors will auto lock after a short time later.

 

I'm afraid not, not even the keyless entry cars automatically lock, you still have to do something!

 

You still have to press the little button on the door handle to lock the doors.

 

regarding leyless cars not locking themselves.Mine did !
whilst parked with the car running and the smart key next to the centre console I needed to get something out of the boot. I jumped out closed the door and went to the boot, opened then closed it and returned to the drivers door just as it decided to lock itself and me out.
With the keys inside and the car running.

So the smart key is not so smart.

 

Not quite the topic of the thread but related:

When we've driven somewhere and parked up, does anyone know what has to happen for the rear doors to automatically unlock?.
It's one of those things you just do on auto pilot but it seems at least that sometimes I get out of the driver's seat and the back doors are unlocked and sometimes they are not. Not sure what I'm doing differently but so far I haven't been able to find out why.
Should all the doors always unlock if the driver's door is opened?.

 

I've come to the conclusion that the back doors only open if the driver's door is opened first. It seems to be when my wife opens the front passenger door first that the rear doors stay locked.

I don't know if us having child locks on has any effect but wouldn't it be better if the doors unlocked with the driver's door regardless of whether it was opened first?.

 

Rear doors can be opened before the front doors but you must pull door release twice - it's to prevent accidental opening.

 

our optima was the same, unless drivers door opened first you could not open rear doors from the outside unless you press ether unlock buttons on the front doors, and our new sportage is the same if wife opens her door first they stay locked even if i open my door.
Hope this helps