Q: I recently heard that batteries are the most frequently replaced component in cars that are three years old. Any idea what might be the cause here? Might this have anything to do with the proliferation of automatic start-stop systems to save fuel? Or the "vampire" effect of trickle-powering electronics to preserve settings, etc.? Or are automakers just using cheaper batteries?

J.G., Chicago

A: Carmakers would not benefit from installing crappy batteries. More likely, batteries are not getting adequately charged when driving. The vampire effect from infotainment and other power hogs contribute to key-off drains. This is particularly an issue when drivers leave their remote keyless entry fob in the car. Plus, telemetry during down time (electronic control module updates, maintenance data, etc.) taps power and is most harmful to already-undercharged batteries. A battery that is chronically undercharged will develop a condition called acid stratification where stronger acid settles to the bottom with weaker acid near the top. It shortens the battery's life.

Q: Saw something for the first time in all my years of driving that you may have seen yourself. It happened one evening on an area toll road when a pickup truck about 300 yards from an open road toll booth turned on some very, very bright LED lights that were around his rear license plate. He drove through the toll, then turned them off after a couple of hundred yards. Is he trying to blind the license plate camera from reading his?

L.K., Chicago

A: A spokesman for the Illinois State Police confirmed your suspicion. People use numerous ploys to avoid paying tolls. Some work, some don't. If the pickup driver is caught, he will be charged with improper license plate illumination, toll avoidance and confiscation of the LED lights. Paying the toll is cheaper than paying the fine.

Q: The headlights on my Jeep Liberty click on and then click off while driving. It is very scary, as the roads in Florida are quite dark. I took the Jeep to the dealer and they kept it for two days, but couldn't find a problem or see it happen. A private mechanic had it for three days and said he couldn't find anything, either. This is driving me crazy. Can you give me any promising advice?

S.F., Del Ray Beach, Fla.

A: Do the people at either of these shops work the midnight shift? Someone needs to test-drive the vehicle under the conditions in which the problem occurs.

Q: Your suggestion of softer-riding tires to solve C.M.'s dislike of those on a Hyundai Sonata totally solved the same issue on my 2013 Toyota Avalon Limited. Replacing its hard Bridgestone Turanza low-profile 225/45R18 tires with the same size Pirelli Cinturato P7 All Season Plus miraculously delivered the safe, quiet and comfortable ride the car should have had when delivered.

H.Z., Park Ridge, Ill.

A: Wise you are, said Yoda. Another option suggested by a reader is to swap the 18-inch wheels for 17-inch wheels and install taller tires.

Bob Weber is a writer and mechanic who became an ASE-certified Master Automobile Technician in 1976. He maintains this status by seeking certification every five years. Weber's work appears in professional trade magazines and other consumer publications. His writing also appears in automotive trade publications, Consumer Guide and Consumers Digest Send automotive questions along with name and town to motormouth.trib@verizon.net.