Her husband struggled to remove the plastic casing, though, and when he used a screwdriver to pry it off, it shattered. What came next was even worse. Her Nissan dealer wanted $250 to order a new one.
Mrs. Musall, a real estate agent from Fishers, Ind., figured "10 bucks, we'd be done."
"But apparently, it's not a do-it-yourself thing if you don't know what you're doing," she said.
Car owners hoping to trim expenses are sidestepping the mechanic and plunging into their own repairs -- or trying to, anyway. Their efforts can backfire, costing more in the end and creating do-it-yourself horror stories.
Mechanics say they've seen it all in recent months, including incorrectly applied brake pads and antifreeze poured into engine blocks.
"A lot of people, they're in dire straits," said Pam Oakes, the owner of Pam's Motor City Automotive in Fort Myers, Fla. "They try to do this stuff at home in their driveway."
The results can be frustrating, and sometimes outright dangerous. Beth Riggs, who lives near Lebanon, Ohio, took her Chevrolet TrailBlazer to a car-savvy neighbor nearby who charged $500 to replace her front and back brakes, far less than the going rates at nearby repair shops.
Later, on a highway ramp, her car suddenly froze up and pulled to the side of the road. The problem? Ms. Riggs says her neighbor neglected to put a certain part on a bolt of the wheels, setting off a chain reaction that caused the tires to lock up.
The car had to be towed, and Ms. Riggs ended up paying an additional $400 to have it fixed at a Cincinnati auto shop.
THOUGH THEY ARE well-intentioned, people forget that today's cars are vastly more complicated than models made just a few years ago. Most are so computer-controlled that owners can't spot problems without access to specific tools and data programs, said Dave Striegel, the owner of Elizabeth AutoCare in Elizabeth, Pa.
Even jobs that were once simple, such as changing the oil, can take hours to complete now.
"They're not able to do nearly the work that they used to do -- it's even going beyond the heads of technicians who aren't keeping up-to-date," Mr. Striegel said.
Even so, some car owners remain undeterred. On Yahoo, queries for the terms "car repairs" and "salvage auto parts" are up 77 percent and 99 percent respectively in just the past month, according to the site's data.
Other car repair search terms remain at three-year highs, reflecting "a renewal of the good old American independent spirit," said Vera Chan, a senior editor for the site.
The urge to cut out the middleman extends to even the wealthy, said Stephen Viscusi, a New York-based writer and career consultant.
"We feel the need to be frugal and save money," he said.
That doesn't mean repairs come easily, though. Mr. Viscusi tried to change the oil on his Mercedes-Benz sedan and wound up with it all over his face, a situation he likened to an episode of I Love Lucy. He also struck out replacing spark plugs on his BMW.
Auto shops say there's an easy way to save money: Just be up-front about the repairs you've tried at home. Most do-it-yourselfers, perhaps out of sheer embarrassment, play coy when mechanics start asking questions about what went wrong with the car, said Paul Lambdin, the owner of Cary Car Care in Cary, N.C.
"Rather than saving themselves time and money by telling us the whole story, they'll just say, 'This doesn't seem to be working,' without going into the details of what they've already done to destroy the whole mechanism," Mr. Lambdin said.
TO PIECE TOGETHER what went wrong, mechanics typically have to start asking questions, and lots of them, said Ms. Oakes, of the Fort Myers repair shop.
"It's like, 'What's the real story?' " she said. "You play the 20 question game, and then it comes out."
People who try the at-home tinkering are usually out of work or low on cash, said Evan Brodof, of Evan's Auto Repair in suburban Cincinnati.
Many of them are men who work as contractors or handymen in another trade and think they can apply those skills to car repair, said Craig Douglas, the owner of ASG Automotive in Indianapolis.
"It's those people who have that mind-set, "Hey, I can fix this, I can fix that,' " Mr. Douglas said. "Bob the Builder-type people."
Mrs. Musall, with the broken taillight, says she has learned her lesson. They won't be laying his hands on the car anytime soon.