Interesting reply from the local (Czech) Honda official: "The internal motion sensors are only in UK Jazz models so your chihuahuas are safe."
As for the posts about "cooking dogs in the cars": Please explain to me how I can cook my dogs in the car parked in the UNDERGROUND GARAGE? Thanks.
NEVER ever leave a dog in a locked car.
NOT even in an underground garage.
Put a maximum/ minimum thermometer inside your car to see how hot it gets on a summer day even in shade.
If you get into the habit of leaving dogs in cars, you'll also do it above ground too.
If you travel with the dog in the boot area the temperatures can also get very high when the sun is on the glass rear windscreen.
On a warm sunny day, the temperature inside an enclosed car can easily reach 50/55C. On a hot day it can easily reach 60C or more. A locked car is just a metal box with glass and minimal ventilation. Leaving windows open does not help.
In UK, if a dog is locked in a car, you are permitted to break into a car to rescue the dog, not so with children! Mind you, the British treat dogs better than themselves.
It is your dog. It is up to you. The dog cannot release itself. You are responsible for it's welfare and. in UK, can/ will be prosecuted.
