Q Does undercoating a car work, and is it worth the expense?

A If you're asking about rust-proofing, Consumer Reports magazine suggests that you decline. Today's cars have much better corrosion protection than cars of the past. Modern vehicles almost never develop serious rust problems during their first 10 years.

Soundproofing might be another story. Although the magazine has not weighed in, several car owners have said that undercoatings work well to cut down on road noise, a major contributor to noise in the car.

However, before shelling out the money, consider how much you value a quiet car. Test-drive the car. Some cars are quieter by design than others. And, if it's noisy, try to determine what kind of noise you hear and where it's coming from: the road, the exhaust or the wind over the car. Sound-proof coatings typically diminish only the road noise.

If you decide to undercoat for sound, practice due diligence. Ask for a demonstration of a car with and without the coating so you'll know what to expect. Also, check on guarantees or warranties.

Unloading microwave Q What do I do with an old microwave that works but that I don't want anymore? Can it be donated? Where?

A Microwave ovens, like other major appliances, must be recycled. Call a recycling dealer or community recycling office for suggestions on how to dispose of it properly. Often, they charge a small fee.

Many agencies will not accept such donations because the appliances can become a financial liability for recycling. Call the agency and ask. Or dial 211, United Way's First Call for Help, and ask for the name of an agency that might take your microwave.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. Fixit appears everyday except Friday.