Re: Hindsight is a wonderful thing
Yes, it is, but sometimes you need to understand the risks of doing too much.
Sometimes you need to just rely on your design, and after proving you have made it as good as possible, let it go. One example of this is the ascent stage of the lunar lander. This rocket was only fired ONCE for the takeoff from the moon. It was NEVER tested since the act of testing it with the fuels/oxidizers involved degrades/destroys the engine itself. They built it to be as bullet proof as it could be and over engineered it a bit more. It used a hypergolic fuel mixture and simplified fuel flows (I believe they used gas pressure to empty the tanks, and it had only one speed (ON!). Guess what, it worked EVERY time. As for my vehicle that I use every day:
1) Do you presently have a spare can of fuel in your car?
No, but I do watch my gas gauge, and if I forget, I have a AAA (us, AA - UK) card that will get me some.
2) Do you have a spare can of water in your car?
No, but on the time the cooling system failed (it was a couple of months ago), I could pull over and park, waiting for a tow.
3) Do you have a torch (flashlight) in your car?
Yes, it is only common sense. This is a small device that takes up little space, and has other benefits.
4) Do you carry warm clothes and/or blankets (in case you get stuck in a traffic jam etc. overnight)?
No, but in the cases where this might be a problem, I was traveling to a ski area overnight, and DID have some warm clothes I was actually wearing.
5) How regularly do you check the air pressure in your spare tyre?
While not on my vehicle, automatic pressure telemetry is now required on new vehicles. I do get my tires rotated on a regular basis (5,000 miles) and it is checked there.
6) When did you last check that your brake lights were working OK?
Thankfully the vehicles electronics DOES check this (modern cars!). As for older vehicles, no brake lights will usually get you rude warnings (horn honks) from people behind you. Good practice to check every so often, when servicing.
So while you do bring up valid points, overthinking things like this can get too extreme. Thankfully the faults described to not cause my vehicle to spontaneously destroy itself, whereas lack of a proper computer backup, can be catastrophic (to say the least).