•Q. With talk about the potential (though unlikely) event of a large solar flare directly hitting Earth, some high-tech engineering types are discussing the merits of using homemade Faraday cages to protect electronics and power-generating equipment and vehicle computers. Rather than place in the garage a large, galvanized steel container that’s large enough to park a car in after the container has been lined with insulation and add a conductive layer around the car, I’m thinking it would be more practical to just buy a spare car and maintain it, albeit one that does not have any electronic controls. I’m thinking a carbureted vehicle built before the ’80s would do the trick. The question I have is, Would a car with a carburetor built prior to 1980 continue to run (assuming that it can run OK prior to this potential event) after Earth has been hit with a large solar flare, similar to the Carrington Event of 1859, which was strong enough to cause electrical shocks to telegraph operators? Also, what would be a suggested vehicle to keep for such an event?•

RAY: Well, we all remember what chaos the world was cast into after the 1859 Carrington Event. Life, as we knew it, was extinguished. I mean, try finding a telegraph operator today! Where are they? You think it’s a coincidence that you can’t find a telegraph operator anymore?

TOM: Doesn’t anybody screen these letters?

RAY: Actually, I think it’s a very reasonable question. We’ll do our best to help you out.

TOM: OK. In order to avoid being automotively stranded by some sort of major, Earth-wide electrical disturbance, you need to go back to before computers were used to manage engines, and before electronic ignition. That would put you in the early 1970s.

RAY: I think the car for you is a 1972 Dodge Dart. It’s proven pretty reliable. Since it has a nerdy cult following, there are lots of parts still available for these cars. It has a one-barrel Holley carburetor and no important electronics that would be affected by electromagnetic radiation. In fact, it doesn’t have any electronics at all.

TOM: Or, here’s another idea: How about a nice, 1971 Chevy Kingswood Estate Wagon? That’s got a nice, simple, carbureted V-8 engine, and the fake wood paneling should survive any electrical event. Plus, a full-size station wagon will give you plenty of room to carry around the provisions you’ll need for the next 50 years.

RAY: But whatever car you get, just to be on the safe side, you might want to take the radio out and wrap it in tinfoil.

TOM: But don’t use all of your tinfoil. You’ll need to have enough left over to make your hat. Godspeed.

•Q. I have a 2003 Ford Explorer Sport Trac with only 22,000 miles on it. I took it to my local quickie-lube place for an oil change. They offered to do a free alignment check. My boat-payment antennae went up immediately. They said the lower ball joints were worn and needed to be replaced. It drives like the boat it has always been, and I’ve noticed no unusual tire wear. How likely is it that the ball joints are worn? Is there any significant risk to not getting them replaced? Would I notice any indications that they’re failing?•

TOM: Very, yes and no.

RAY: On a 10-year-old car, I think it’s very likely that your ball joints are worn out. Even though you have low mileage, the grease inside the joints tends to dry up, and that causes the joints to fail.

TOM: If you don’t trust these guys, the easiest way to confirm this is to take the car to another mechanic and ask for a second opinion. If you don’t have a mechanic you trust (which everyone should), try searching at www.mechanicsfiles.com. That’s a nationwide database of good mechanics who have been personally recommended by other readers and listeners of ours.

RAY: It’s unlikely that you’d be able to determine, by driving the car, whether your ball joints are bad. You won’t feel anything until it’s almost too late. Just before the ball joints break, you may feel a shimmy in the wheel and have time to say, “Hmm, what’s that?”

TOM: But your mechanic can tell by testing them. He’ll put the car up on the lift and grab each tire at 9 and 3 o’clock, and try to push and pull it. He’ll do the same thing at 12 and 6 o’clock. If the ball joint is good, there should be absolutely no back-and-forth movement in the wheel whatsoever. If it moves at all, the ball joints are shot and you need new ones.

RAY: And what if you just wait? Is there a significant risk? Well, how does this sound: You’re driving at 70 mph, and all of a sudden you feel a strange little shaking. As you furrow your brow to wonder what’s causing the vibration, your wheel falls off.

TOM: Then, as your life is flashing before your eyes, you can quietly apologize to the guy who tried to tell you that you needed ball joints. So get the second opinion if you don’t trust this guy, but don’t just ignore the warning.

Got a question about cars? Write to Click and Clack in care of this newspaper, or email them by visiting the Car Talk website at www.cartalk.com.