QDear Tom and Ray:

I'm writing about overly bright headlights. I have been calling them halogen headlights, but I saw in another response you gave that they are technically xenon or high-intensity discharge headlights. Well, I'm writing to let you know that when a car is coming at me with those lights, it feels as if lasers are piercing my retinas! I detest those things. And yes, I do put my brights on when a car approaches me with those on. I doubt they get the message, but it makes me feel better. I have spoken to others who have this same loathing for and physical reaction to those xenon/HID lights. My question: Do you know of a grass-roots movement that is opposed to them? -- Chris

ARAY: Actually, there's a real effort under way to understand the particular problems with HID lamps, because so many people have complained -- and continue to complain -- about them.

TOM: Scientists at the National Highway Traffic Safety Administration have been studying the issue of "glare" for several years now in response to overwhelming complaints from the public. And as they wrap up their research, the two issues they're focusing on are the xenon/HID technology itself and the mounting height of headlights.

RAY: In terms of the mounting height, there are people who believe that car makers are allowed to mount headlights too high, and that lowering the height requirement for headlamps might really help cut down on glare from oncoming traffic.

TOM: The other issue they're looking at is whether there is a particular problem with the blue HID bulbs you mention, Chris. Is the problem that they simply produce too much light? Or is it the type of light they produce?

RAY: There's evidence that light containing a lot of short waves (like blue) produces more discomfort in the human eye than longer light waves (like red or orange).

TOM: NHTSA is studying the data and hopes to propose some new rules by the end of 2005. When they do, we'll let you know here in the column, because at that point they'll want to hear from the public. If enough people support the rules, they'll go into effect and you'll eventually see an improvement on the roads. In the meantime, you'll just have to do the best you can and squint, Chris.

Dear Tom and Ray:

I have a 1989 Jaguar XJ6. And every 3,000 miles, when I change the oil, I also drain out three quarts of the automatic-transmission fluid by removing the transmission drain plug. Then I put in three new quarts of ATF to replace it. I'm hoping this will prolong the life of the transmission. Am I correct? -- Eliot

TOM: Well, you're certainly prolonging the life of the company that makes the automatic-transmission fluid, Eliot.

RAY: And you're also lengthening the life of your transmission. As you drive the car, the transmission fluid slowly gets contaminated. That's normal. But as the miles pile up, it gets more contaminated, and does a lousier job of lubricating.

TOM: What you're doing is draining out some of that fluid every 3,000 miles. You can't get all of it out because of the way the transmission is configured -- your car's transmission holds 8.5 quarts -- but you're draining out about a third of that contaminated ATF, and refreshing the mixture with some new stuff.

RAY: It's easy to do, and it probably does have some benefits. In fact, I think I smell a new $39.95 recommended service at our garage!

TOM: An even better case can be made for doing it on your car, Eliot, since a rebuilt transmission for this beast would probably cost you as much as a one-bedroom condo in a mid-size city.

RAY: Now, if you could only change a third of the electrical system every time you change the oil. . . .

Got a question about cars? Write to Click & Clack in care of The Post, or e-mail them by visiting the Car Talk Web site at www.cartalk.com.

(c)2005 by Tom and Ray Magliozzi

and Doug Berman