[neilgorin]

Modern computerised cars.

My wife's car eats a battery every other October as soon as we get the first frost.

First sign it's wrong is you approach the car and the wipers slowly move across the screen.

Next sign is you start the engine and it says "Power Steering Failure" followed by "Low Oil Pressure" and "Service Gear Shifter". They all go as you drive off.

The next morning the battery is dead. Dead dead, recharge it and it's dead again the next day.

New battery cures it for exactly 2 years. There's never been a power steering fault, a oil pressure fault or an issue with the shifter, but the battery drops enough that the computer gets a stray signal and thinks that there is.