But her husband struggled to remove the plastic casing, 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.
Musall, a real estate agent from Fishers, Ind., figured "10 bucks, we'd be done."
"But apparently," she said, "it's not a do-it-yourself thing if you don't know what you're doing."
Car owners looking 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 engines.
"A lot of people, they're in dire straits," said Pam Oakes, 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 Chevy Trailblazer sport utility vehicle 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? 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 Riggs ended up paying an additional $400 to have it fixed at a suburban Cincinnati auto shop.
While well-intentioned, many people forget that today's cars are more complicated than models made just years ago. Most are so computer-controlled that owners can't spot problems without access to specific tools and data programs, said Dave Striegel, 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 a lot of technicians who aren't keeping up-to-date," 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.
Auto shops say there's an easy way to save money: Just be upfront 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, 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,"' he said, "without going into the details of what they've already done to destroy the whole mechanism."
To piece together what went wrong, mechanics typically have to start asking questions, and lots of them, said Oakes, of the Fort Myers repair shop.
"It's like, 'What's the real story?"' she said. "You play quiz master with them. ... 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, owner of ASG Automotive in Indianapolis.
"It's those people who have that mindset, "Hey I can fix this, I can fix that,"' Douglas said. "Bob the Builder type people."
Musall, with the broken taillight, says she's learned her lesson. Her husband won't be laying his hands on the car anytime soon.
"It's all fixed," she said, "and he's not going to do any more car repairs."