RAV4 hosts feast for uninvited guests

Dear Car Talk:

I have a 2018 Toyota RAV4. Last weekend, I bought a 20-pound bag of birdseed for the feeders in my backyard. It was a cold, rainy, miserable day, and I decided to wait to bring it in the house.

A couple days later, I opened the back door of the car and a hole had been chewed in the bag, and there were sunflower seed shells on the floor.

How on earth did the mice (I’m assuming) get into the car? — Julie

RAY: They may have already been using your car as an extended stay Marriott, Julie. They may have been as surprised as anyone that it suddenly turned into a bed and breakfast.

Mice are notorious for seeking out warm places to sleep (and perform other functions) and for being able to squeeze into very tight spaces. I wouldn’t be surprised if they had already discovered that your engine compartment or ventilation system provided a wonderful, dry place to sleep after you got home at night.

It’s not hard at all for them to get in there. They can climb up your tires and get into the engine compartment. From there, they can make their way to the cowl at the bottom of the windshield, where fresh air comes into the passenger compartment.

There’s a plastic grate in there, but mice are good at squeezing through small openings. Or chewing holes in things they can’t squeeze through. From the fresh air vent, it’s smooth sailing to the air ducts and to the interior of the car.

My guess is that some lucky mouse found the birdseed and posted a picture on Twitter. #Jackpot!

It’s a tough problem to solve. The best solution is a well-sealed garage. But I would suggest you clean out the remaining food to discourage them. You might also ask your mechanic to check the grating that protects the fresh air vent, in case they damaged it. See if he can find you a titanium replacement.

And look on the bright side, Julie. Your car may be a mess. But you’re responsible for one of the greatest bonanzas in mouse history. It’s the mouse equivalent of the First Thanksgiving. Two hundred years from now, mouse textbooks will teach young mice about “Julie’s RAV4 Miracle.”

Why don’t cars have battery monitors?

Dear Car Talk:

I have a question about a dashboard accessory. It came to mind after my wife and I prepared to go on a little 350-mile trip to spend a few days at our daughter’s house.

I checked the tire pressure and oil level, we packed the car, set the GPS and congratulated ourselves for an on-time departure. Then I pushed the ignition switch, only to hear clicking, and a weak hum, illuminated by dim headlamps.

I guessed the problem immediately; our 2013 Murano’s 7-year-old, original-equipment battery was dead. OK, no surprise there. I was thankful it died before the trip got underway.

A new battery later, and we were on our way. But it made me wonder: Why don’t cars have starter-battery meters to warn of dying batteries? Even if it’s not perfect, it might alert us to imminent battery death and save us from sitting in the garage rather than visiting our distant children. — Wayne

RAY: Sure. It could be another warning light we all ignore -- like the tire pressure warning light and the check engine light.

I’m sure it’s possible, Wayne. Even though it’s not nearly as easy as testing a D-cell that powers your flashlight or monitoring the charge on your iPhone. Because a 12-volt car battery has to provide a massive amount of power all at once to start the car, you really have to measure the resistance of the electrolyte.

There are testers you can buy and use at home that claim to test your car battery and cost anywhere from $20 to $200. But if you want one that gives you the same information that we get at the shop when we test the health of car batteries, you’re probably going to spend at least $100-$150. That may make it cost prohibitive to include as standard equipment on every gasoline-powered car.

Of course, with the costs of electronics and computerization dropping every year, that calculation may change, but possibly not before electric cars take over and make this whole issue of the “starter-battery” moot.

So in the meantime, if you don’t want to get stuck with a dead car battery, my advice is to replace your battery every five years. In my experience, batteries rarely die before the five-year mark. But after that, they’re essentially on borrowed time.

You may say, “Well, why should I spend $150 on a battery if my old battery’s not dead yet?” And the answer is, because it’ll still cost you $150 six months or a year later, plus the towing fee, the inconvenience, the missed dinner at your daughter’s house, and the indigestion from having to eat at the Only Dropped It Once Burger at a highway rest stop.

And since most people change the battery just once during the time they own their car, why not do it on your schedule, as preventive maintenance and then not have to worry about it for another five years?

Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.

About the Author