The honk is not the car locking, it's the alarm engaging as it usually comes from the alarm horn. Most cars with no alarm system don't make more than the mechanical sound of locking the car and the visual aid of the signal lights blinking.

There are some cars that use the car (not alarm) horn when locking so maybe their central locking system is connected to it, although it never looked like a factory option, rather an OEM alarm or something similar.

I have never seen a car that doesn't honk when you lock it, alarm system or not (and I rarely see cars with alarm systems around here). Maybe this is a regional difference. Do you live in North America?

The "honk on lock" thing does seem to be a North American thing. I would always be startled and annoyed when locking my rental car in the US.

I haven't noticed cars anywhere else doing this, but I'm not that well traveled.

In the UK it's illegal to sound the horn when the vehicle is stationary, or between 23:30 and 07:00 in a built-up area, so someone who brought one of these auto-honking US vehicles to the UK would have to lock it by some other means?

A quick reading of the rule seems to imply that it only applies on roads, not for example in your driveway or a parking lot.

See: http://www.legislation.gov.uk/uksi/1986/1078/regulation/99/m... , https://www.legislation.gov.uk/ukpga/1972/20/section/196/ena...

FWIW a lot of UK cars are parked on the street at night, rather than on private land.

https://www.racfoundation.org/motoring-faqs/mobility#a6 suggests it's about 35% of vehicles in large settlements.

I turned mine off in my Dodge Caravan after owning it for a day. It was pretty easy to find in the settings. The lights flashing are enough feedback for me.

Europe. Making the horn sound seems excessive compared to just flashing lights. Perhaps some regulation in Europe discourages manufacturers from using anything that causes unneeded disturbance.

It's a light honk, here's an example: https://youtu.be/_rpEtxBo00U?t=23

I don't find it too bothersome, but maybe I'm just used to it. In some other videos people are suggesting that it can be disabled on most vehicles by holding the lock and unlock buttons simultaneously for 2 seconds.

> There are some cars that use the car (not alarm) horn when locking

Every GM vehicle I have ever owned honks (via the car's horns) on the 2nd lock.

(a) there is not a seperate alarm horn (b) removing the horn, also disables the 2nd lock honk.

I don't think power locks were standard until roughly the early 90's. Same with those completely useless "alarms".