Q. It drives me crazy that my husband, in his late 40s, floors the accelerator pedal in our fuel-injected 2003-07 cars just before turning off the engine after parking. He gives no reason for doing it and just says he is following his father’s advice. Is he doing the car any good? —K.R., Tinley Park.

A. My grandfather did the same thing with his carbureted autos in the 1950s. He wasn’t doing them any good because his action caused a large amount of fuel that wasn’t being used with the engine off to wash lubricating oil from cylinder walls. That created unwanted friction, which is harmful to engine life. But your husband is doing no harm because carburetors have been replaced by fuel-injection systems, which immediately shut off gasoline flow when the engine is turned off. However, your husband is wasting fuel by flooring the throttle. To keep peace in the family, say you’re just curious and ask him to show you anything in print that recommends flooring the throttle. If his father is still around, also ask him. It’s a sure bet they’ll never come up with anything.

Q. Lots of damage is caused by people entering or leaving vehicles in parking lots. Do any cars have sliding front doors, like the rear doors of minivans? —W. M. , Streamwood

A. How far back do you go? The last car from a major automaker built with sliding doors was the sleek 1954 fiberglass-body Kaiser-Darrin sports car. Its doors slid into the front fenders. Only 435 were built, but some 400 are known to still exist.

Q. Regarding your article challenging the newspaper advertisement for the like-new 1969 Chevy Z28 “$12,400” Camaro (Jan. 10-11 AutoTimes), it’s worth $100,000-plus. Could that car possibly be real? I say the ad is a scam. —B.P., Huntley

A. I agree, unless the seller is Santa Claus.

Q. About that 1969 Z28 Camaro with the low price, I saw a similar ad for a desirable 1970 Chevy Chevelle SS396 muscle car for a ridiculously low $4,400. Nobody answered the phone listed in the ad, but it let me e-mail someone who asked me to send money to an independent party via an “escrow service” and that my payment would be withheld until the car was delivered to me. How much would you bet that I’d never see the Chevy after I sent the money? —A.N., Chicago area

A. I’d bet the farm.

Q. I’ve seen similar ads for desirable 1960s muscle cars like that Z28 with pictures of the cars in great condition. Curious, I followed up on one and was asked to wire a $3,500 down payment for a 1967 Ford Mustang, setting up a Yahoo Finance account of some kind to wire the money via the Internet — and they would ship the Mustang via car carrier. I said I worked for an airline (which I do) and that I’d fly to a location and pay personally for the car. I never heard back. Surprised? —S.M., Rolling Meadows

A. I’m surprised con men are still running such ads. It possibly means there are a sufficient number of unwitting people getting fooled by such ads.

Q. I’m afraid of a dead battery in my car because I plan to garage it until roads are clear of snow, ice and salt — and that could be months from now. Should I hook the battery to a charger? —F.C., Hillside

A. Get a compact 12-volt battery maintainer, not a charger, from an auto supply outfit and just plug it in, says collectible car expert Larry Claypool of Frankfort’s Vair Shop. The maintainer keeps the battery properly charged, and never overcharges it. Once the battery is fully charged, the maintainer automatically shuts off, then turns on again as the battery level drops.

Q. My son has a totally customized 1968 Camaro in which he’s installed a mighty 427-cubic-inch V-8. The V-8 has only 15,000 miles on it, and the car should be an easy sell because of that engine and the fact that it’s a bright red convertible and he has moved to Southern California. However, the Camaro has minor rust because it’s from Chicago. My son feels it’ll sell faster if he spends $5,000 to repair the rust, paint the car and install a new stereo system. Your thoughts — and what’s the car worth? —L.T., Downers Grove

A. It’s very difficult, if not impossible, to put values on customized cars because no price guides contain figures for them. Also, the “minor” rust might turn out to be major. In any case, replace rusted areas with new sheet metal, not body filler. A decent paint job will cost at least $3,000 — an outstanding job far more. I’d sell the car “as is” because it’s likely your son will never get back money he puts into it. And forget the new sound system because chances are the car’s new owner will remove it and install a system more to his liking.

Q. My small 1994 Geo Metro three-cylinder car with a manual transmission gets 45-50 mpg. With today’s technology, you’d think more automakers could offer such a car. —X.A., South Holland

A. Your car weighs under 1,700 pounds. I tested one when it was new and found it had frail fenders and doors and too-tiny wheels and tires. The ride was jarring and the rear seat was just for tots. Also, highway acceleration was marginal and, of course, it had no modern safety equipment. Consumer Guide magazine said the car “was designed for the slow-paced roads of Japan.”

Q. I’d like a 1968 Buick Wildcat convertible but can’t find one anywhere. If I locate that car, what’s it worth? —E.G., Oak Forest

A. Try Hemmings Motor News, which has thousands of ads for collectible cars, or a local Buick-owner club. That car is valued at at $6,975 in good condition and at $13,250 in excellent shape. Only 3,572 were built, and most have probably rusted away.

Car question? Send it to Dan Jedlicka, Chicago Sun-Times, 350 N. Orleans, Chicago 60654, or e-mail dan@danjedlicka.com. Include name and hometown.