When Amy Dowdall watched her 70-year-old husband drive up to her house last December in a brand new, convertible Nissan Murano with a salesman riding shotgun, she could barely pick her jaw off the floor.

That's because her husband, from whom she's legally separated, suffers from dementia and wasn't supposed to be driving anywhere, let alone buying a new car.

She immediately explained her husband's medical condition to the car salesman, and demanded that the car be returned.

While the salesman acknowledged that something had seemed amiss with the man, he told Amy Dowdall that there was nothing he could do now that the sale had been completed, Dowdall said.

Since then, Dowdall, who has power of attorney for her husband, has been trying to undo the sale and determine if he was the victim of elder abuse.

Dowdall has been separated from her husband for years, but felt compelled to get involved when his health started to decline. He was diagnosed with an advanced form of dementia called Lewy Body Dementia in October, after undergoing brain surgery for what doctors had thought was Parkinson's disease.

Since the surgery, Dowdall said, her husband's condition has declined to the point where he requires constant care.

He is currently at the Acute Psychiatric Ward of the Jewish Home in San Francisco.

In December, Dowdall was still living in his Bodega Bay home under the watch of his younger brother, Mike Dowdall. But on Dec. 14, Mike Dowdall left his brother to discuss long-term care options for him with Amy Dowdall.

While alone, Dowdall drove himself to the North Bay Nissan dealership in Petaluma, traded in his Nissan Altima Hybrid and purchased a brand new, convertible, 2011 Nissan Murano. Including numerous bells and whistles, the car cost $62,130.

In the contract, Dowdall agreed to make $923 monthly payments. "He never in a million years would have agreed to this in his sound mind," Amy Dowdall said, describing him as a frugal man who kept expenses meticulously.

With the help of a friend, Bob Wahl, Amy Dowdall left messages at the dealership but didn't hear back. She then hired Petaluma attorney Michael Baddeley, who wrote North Bay Nissan in early February, requesting that the contract for the vehicle be rescinded.

The Argus-Courier made several calls to the dealership for comment, but never heard back.

Greg Dexter, who is owner of the dealership, called in response to the letter, said Baddeley, and told him that he had talked to Wells Fargo, the bank that financed the loan for the car, and offered a settlement. However, he didn't tell Baddeley what the settlement offer was.

Dowdall followed up with a Wells Fargo representative, who apparently said she wasn't aware of any settlement offer.

Baddeley pointed to a California law that says a person with an "unsound" mind has no power to make a contract and that any contract such a person does enter into is subject to being undone.

He wrote that Dowdall's condition should have been apparent to the salesperson. He pointed to the fact that Dowdall paid what seems to be top dollar for the vehicle and purchased about $10,000 in expensive dealer add-ons, including fabric and paint protection and security measures, without negotiating.

Dowdall's doctor, Paul Larson of the University of California San Francisco Medical Center's neurological department, also confirmed Dowdall's "markedly impaired judgment, lack of impulse control, aggressive and compulsive behavior and an almost total lack of insight into his condition" in a formal letter.

Still, local experts in elder abuse said assigning blame in cases like this is not always straightforward.

Individuals with dementia can sometimes present themselves for brief periods of time as capable, and most car salesmen are not trained to tell if a person is mentally incapable, said Kira Reginato, an elder care manager in Petaluma who has worked with Amy and her husband and maintains that she thinks the deal was a bad one.

Richard Hechler, an elder abuse attorney who worked in the San Francisco District Attorney's office, described the case as a "gray" one.

"If this guy wasn't declared incompetent, he had the right to do whatever he wanted," he said.

But, he added, "You'd think that it would be a good business practice to inquire and make sure you're selling to someone who is properly able to contract."

Dowdall is currently considering whether to take further legal action to have the contract rescinded.

In the meantime, she has notified Wells Fargo that she doesn't plan to make the monthly payments, as Dowdall cannot afford them.

Meanwhile, the new car is sitting in a garage with about 40 miles on the odometer.

(Contact Jamie Hansen at jamie.hansen@arguscourier.com)