It's taken almost a decade, but established automakers may finally be mounting a legitimate challenge to Tesla. Only a small percentage of electric vehicle shoppers are completely loyal to Tesla, according to a new J.D. Power study on EV buying trends.

Tesla ranked highest among luxury brands, with 27% of respondents who are considering a luxury electric car naming a Tesla as their top choice. However, only 4% of that group said they were only considering a Tesla, showing that the Silicon Valley firm is being cross-shopped against other brands at a high rate.

"One could argue this indicates that, while Tesla's appeal is clearly formidable, it's not absolute and could be displaced by a worthy alternative," Stewart Stropp, senior director, automotive retail, at J.D. Power, said in a statement.

Echoing previous research, the firm also found that firsthand experience helps nudge people into considering an EV. The study found that respondents were three times as likely to consider an EV even after just riding in one. Among respondents who have bought or leased an EV, 46% said they were "very likely" to consider another one, while only 6% said they were "very unlikely" to consider another EV.

Shoppers may also be willing to consider a hybrid or plug-in hybrid sooner than an EV, the study found. Among those who aren't considering an EV right now, 41% said they would consider a hybrid or plug-in hybrid in two to four years, while 27% said they would consider an EV in the same timeframe.

2021 Ford Mustang Mach-E, left, and 2021 Tesla Model 3, right

2021 Ford Mustang Mach-E, left, and 2021 Tesla Model 3, right

Broader consumer attitudes aside, the study indicates Tesla may not be dominating the high-end EV market the way it once did.

Many years ago Tesla owners were seen to be the most loyal in the industry, and shoppers wouldn't consider anything else.

However, that was in the early days of the company's volume ramp-up, when Tesla would go above and beyond to please customers. Its now more firmly established, with a larger customer base that makes such measures impractical and, perhaps in the minds of executives, unnecessary.

At the same time, build quality remains an issue. Early adopters and hardcore fans may have been willing to overlook uneven panel gaps, poor paint quality, and other blemishes, but that may not be the case with mainstream customers who are less attached to the brand.

Tesla also faces more competition, with more long-range electric cars on sale, or on the way. In a recent interview with Bloomberg, BMW CEO Oliver Zipse predicted that Tesla won't be able to maintain its advantage as established automakers ramp up production of their own volume EV models. With so many on the way (BMW plans to launch at least 13 all-electric models by 2023) shoppers will at least have more choices where, previously, Tesla was the only option.