It seems random at least to me and our Mclaren rep is as usually clueless lol. So why does the car give a long beep when locking? And it's random sometimes it happens while other times it doesn't.
Don't have my driver's manual handy but I think there is something about it in there. Could be the car thinks the key fob is still inside the car? Just a guess.
It does this when the luggage compartment is open. Designed to allow battery conditioner to be plugged in and the car alarmed all the same but to warn you that this is the case.
I leave my car like this most of the time. You can close the luggage compartment with the charger wire passing through the seal but I prefer not and just lay the luggage compartment lid down without closing it fully.
I have noticed this. Handbook says it happens if luggage compartment, engine cover, doors or lights are on. for me it seems to happen when I pull into my garage and with the lights on auto, lights come on for say 60 seconds and if i get out the car when they are still on I get this loud beep when I go to lock it with the fob.....
I guess it has to do with the lights on auto. Did you try turning them of and seeing if the beep persists? I know the long beep your talking about that's the one I was getting.