That may seem a strange sentence coming from a computer science person like me, but at this moment i'm hating electronics.
Today i lost a lunch with some friends from one of the local LUGs because the Renault Megane we bought second hand two weeks ago decided to act weird. This car is equipped with a proximity sensor (maybe RFID?) that comes in a card, so to open it you just have to go near the car and open it. And to start it you just have to press the brake pedal and push the "Start" button.
My father did this at 6 am and came back home at 6:30 am to get the keys of the old car because he could not get it started.
This morning one our before the lunch time i did the same, went into the car, pressed the brake pedal and pushed the Start button, and a "Electronics Problem" message came up on the status panel. I still had time so i could have went lunching with the metro, so i got off the car and pressed the close button on the card to close the car.
So i pull off a key that is inserted on the card and use it to close driver's door, but doing that still leaves co-pilot door and back door open.
So i call try to call previous owner of the car, my uncle, and he says he never had this problem.
Then i go home, pick up the car's manual and see it says there's a mechanical lock on doors you can use to lock them, good! Back onto the car i discover there's no suck lock on my car :-@
I go home again, look into the internet a Renault number, phone them and i explain them the problem. The dude says that i should get onto the car, press the "lock doors button" and then go off it and close driver's door with the key. Back onto the car i try that, doesn't work either, opening driver's door unlocks all other doors.
At this point my mother and I were already pretty desperate. At that moment i remembered a friend whose sister had a Megane too. I phoned her and luckily she was with her sister. And bam! she had the solution, it seems the car thought it was powered on, so all i had to do was put the card onto the slot that there's on the car, push the "Start" button twice and then a "Please remove the card" message appeared, so the car thought it was off, we got off the car and could even close all the doors using the card buttons.
We still did not try to get the engine started again, that will have to wait for tomorrow, but at least we could close the doors! Unfortunately more than hour had passed with all that and i could not make to the lunch :-(
So next time you design something cool with electronics, please think of the failure scenario and that a mechanical way to fix it is always welcome!