"Some people are in for a rude awakening," said Bobbie Herron, director of digital sales and marketing at Garber Automotive Group in Saginaw, Mich., at the Digital Dealer Conference & Exposition here.
Opinions at the show, which brought together hundreds of dealership staff, vendors and industry experts, varied widely on how prepared auto retailers are for Google's changes.
But few dispute that mobile car shopping is on the rise, representing almost half of the online contact between consumers and dealerships today.
Herron spoke here after presenting a session on how to hold third-party shopping sites accountable for the amount of traffic they send to a dealership.
Herron said 47 percent of the online traffic at Garber Automotive's dozen-plus stores is generated by mobile devices.
The algorithm changes potentially drop businesses down a search page if they lack websites that are easy to navigate whether the consumer is shopping via desktop or mobile, she said.
"It'll force their hands and a lot of them are going to lose their rankings because of it," Herron said.
Google plays a significant role in the online shopping journey of many car buyers. Consumers may start by searching for such phrases as "used cars Tampa" and end by using the click-to-call function on a dealership's Google link to reach a salesperson.
Consequently, many dealerships use a quarter or more of their digital ad budgets to buy paid-search ads on Google that sit atop the first page of a Google search.
Dealers also work with vendors to ensure that content on a dealership's website and digital marketing provide a high ranking in the free, or organic, results of a search.