Practical Plastic

"That's crucial," says credit-card expert Curtis Arnold, founder of CardRatings.com, an independent consumer resource that rates credit cards. "The interest rates on these gas-rebate cards aren't particularly bad -- like 11.9 to 16.9 -- but if you are planning to carry a balance, you can do better than that" with a low-interest-rate card.

Arnold has his favorites, including the Citi Dividend Platinum Select card. He calls the Shell MasterCard's 15 percent introductory deal "obviously phenomenal," but he doesn't like having to buy a specific brand of gas. Too limiting when scouting around for better gas prices.

One poster on CardRatings.com's forums reports that his Speedway SuperAmerica gas station sells $50 gift certificates for $48, an ongoing promotion. He buys the gift certificate to pay for gas. He uses his 5 percent-rebate Citi Dividend card to buy the gift certificate -- which, in the end, adds up to an 8.8 percent savings on gas.

Arnold says if you play your cards smart, there are significant savings available. "The main thing is paying it off in full," he says. "And understanding how the particular card works. You need to pore over the terms of the offer."

Car Repairs Repaired

That reference to "$100-an-hour mechanics" in a recent column ("An Overheated Car-Repair Bill," Nov. 20) threw a wrench in the Sunday afternoon of several auto mechanics who protested that the service charge may be $100 an hour, but the mechanic is lucky to see $10 to $20 an hour of that. Point taken.

Car repair tends to be a provocative topic. Everyone has a story to tell. Frank Camp of Potomac offers this tip on finding ethical and competent car repair shops: "I have had good luck with the recommendations of Click and Clack" ( http://www.cartalk.com/content/mechx/ ).

Hal Lewis, president of International Automotive Technicians' Network, Chapter 18, a trade group that represents 49,225 automotive technicians in 136 countries, offers this insider tip: Search for reliable auto repairs at IATN's Web site "shop finder" feature at http://www.iatn.net/ (just key in the Zip code). A 30-year veteran of auto repairs from Kennett Square, Pa., Lewis says IATN members sign on to the organization's high standards of professionalism, competence and integrity.

And Rockville reader R. Berman advises that a better resource than AAA's approved repair-shop list is Consumer's Checkbook (a two-year subscription costs $30), the nonprofit consumer group that rates companies, stores and services based on the experiences of consumers who are surveyed. "I certainly would avoid shops that have low satisfaction ratings in Consumer's Checkbook," he says.

Ever wish that customer service reps, stores, manufacturers on online retailers would do things differently? Maybe make "caring about the customer" business as usual? Deadline for New Year's resolutions you think should be on their list is Dec. 21 -- so send 'em now! E-mail details toconsumer@washpost.comor write to Don Oldenburg, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Because of the volume of mail, personal replies are not always possible.