Q: Massachusetts' new license plates are mounted on both the front and rear of all vehicles. Someone told me the reason is that the police want the front plates to use as a reflective surface for radar since the fronts of most vehicles today are plastic. What's your take?

H.H., Melrose, Mass.

A: That little 6-by-12-inch piece of metal is insignificant compared with the rest of the metal on the front of a vehicle. But law enforcement folks have other reasons for displaying a front plate. With modern technology, they can scan huge numbers of cars and locate stolen vehicles. Toll booths photograph the plates to find scofflaws. Some claim that the front plate can be helpful when questioning witnesses to an accident. We think that front plates make most cars look weird and would rather not display one. On the other hand, we don't like fines very much, either.

Q: I have a question about garage door openers. Trying to save money I purchased some LED lights and installed them where the standard 60-watt bulbs would go in the door opener. Coincidentally we started having problems with our door opener remotes. Changing the batteries on the remotes and reprogramming did not solve the issue. I replaced the bulbs with standard 60-watt bulbs and the door opener works flawlessly.

A.K., Tinley Park, Ill.

A: According to the Chamberlain Group — the parent company to LiftMaster, Chamberlain, Merlin and Grifco — LED bulbs can interfere with the signal between the wireless remote and the receiver on the garage door opener. Some brands of bulbs, however, may be OK. It is best to stick with established name brands such as GE, Philips or Sylvania. And look for a marking showing compliance with FCC's Part 15 rules covering radio frequency interference.

Q: I want to change my automatic transmission fluid on my 2002 Lexus GS300 with 96,000 miles. I purchased four quarts of AISIN Type T-IV fluid. The Lexus owner's manual says to use only genuine Toyota ATF Type T-IV and that using other ATF may cause deterioration in shift quality, locking up the trans accompanied by vibration and ultimately damage. Must I use Toyota genuine brand?

B.A., Palos Park, Ill.

A: If a company requires that you use their parts, and only their parts, the company must supply said parts at no cost to the consumer, according to the Magnuson-Moss Warranty Act of 1975. As long as you use a product meeting the Toyota specs, you are safe.

Q: I had an oil change at a Chrysler dealer and drove 625 miles. After leaving work, I drove about 12 miles when the check engine light came on and the engine seized. I had it towed to a nearby Chrysler dealer and they called, saying the oil filter was missing. Where did it go? They said it was vandalism. That means while I was working someone crawled under my van and loosened my filter. Have any thoughts?

J.F., Elgin, Ill.

A: We think that the filter was not properly tightened during the oil change. Unless you have some evil enemies.

Bob Weber is a writer, mechanic and Master Auto Technician.