Q: Hoping you can give me the logic behind lighted dash displays when headlights are off. When I learned to drive, I was taught to glance at the dash (looking for gas level was one cue) and, if it was too dark to see the instruments clearly, I knew to turn on the headlights, which turned on the dash lights. I see people driving in the evening (and even at night) oblivious to the fact that their headlights are not on in no small part because their dash display is brightly lit up anyway. Flashing my lights at them occasionally gets results but is mostly ignored. This is a real safety issue. Why is the dash display illuminated without headlights on?

C.H., Chicago

A: The instrument displays on modern cars are not totally the reflective type of the past. Much of the cluster is more like a computer monitor or smartphone with an LCD display rather than mechanical illuminated by lightbulbs. In short, the driver won't see very much if the instrument cluster is not glowing.

Q: I have a 2005 Ford Explorer maintained by the dealership. It has over 130,000 miles and the dealership says the injectors should have been cleaned long ago. They never have and I have no problems. Should I have the dealership clean them, use an additive or motor on?

W.S. Abington, Mass.

A: Although you could just blissfully motor on, it is not a bad idea to have the injectors cleaned from time to time. That ensures that they properly atomize the fuel for best performance. Of course, adding some fuel injector cleaner to the tank from time to time can't hurt. The fact that you have had no issues tells us that you have been using good gasoline. We suspect that it has generally been Top Tier stuff.

Q: In May I purchased a 2015 Ford Escape. The problem I have is that the front suspension is very loud; when I go over small bumps it sounds like something is loose. I took it to the dealer and they said there was nothing wrong with the vehicle. I told them to try going over the rough streets. Instead they took me for a ride but they went on only newly paved roads. No noise was heard. I am thinking about going somewhere else, please help.

M.M., Beverly, Mass.

A: It is a waste of both your time and the technician's time if the vehicle is not test-driven on the offending types of roads. Shame on them. Front suspension noises on rough roads or speed bumps are often caused by issues with the sway bar, also called the anti-roll bar or stabilizer bar. If they look closely, the techs may discover bad bushings. It is not a life-threatening problem, but it should be fixed. We would take it somewhere else.

Bob Weber is a writer, mechanic and ASE-certified Master Automobile Technician.