I've had a few cars, but none have had so many annoying little faults that cripple the car as my Renault Clio. The car itself is an excellent little runner, but the ECU will cripple the car if the tiniest little thing is at fault, usually a sensor (obviously the weak point on modern cars).
What annoys me is that it doesn't tell me, the owner and driver, that it's a sensor, even though it knows full well that that's what the problem is; the car needs to be interrogated by a diagnostic computer (which is where the dealerships make their money I suppose) before it will relinquish this information.
Today I learned that a tired old battery can cause the engine not to fire, even though there's plenty of power to turn the starter motor. Apparently there wasn't enough remaining power to run the ECU so the engine never received the signal to spark the plugs. What happened to the good old days when cars would start without all this ECU nonsense?
If the battery is old then the ECU should be clever enough to tell me about it, or at least the battery light should come on.
Just seems daft, all this technology and it's not even clever enough to tell me when there's a problem.