China's auto industry has hit a soft patch, but there may be a bright spot.

Auto sales have fallen in China for nine straight months, including a 5.2 percent decline in March.

But electric-powered cars were on display from start-ups and foreign auto giants alike at this week's Shanghai Auto Show. For some in the industry, they say it will be the smartphone-like interface of the new vehicles that will really attract buyers. Those consumers are increasingly using internet-connected services such as food delivery for daily life, especially in China.

So-called new energy vehicles are booming, with sales jumping 62 percent last year. And not just because of the way they're powered.

"The key point is not new energy. The key is smart," Fu Qiang, president and co-founder of electric vehicle start-up Aiways, said Wednesday in a Mandarin-language interview translated by CNBC.

China battery-electric vehicle unit sales forecast (in millions)

Source: Morgan Stanley Research

"The entire decline in the auto industry, much more, in my personal view — of course has some small connection to the economy — but I think the greater reason is that customers right now are not satisfied with the product mix," said Fu, formerly president and CEO of Volvo Cars China.

The nine-month slide in automobile sales in the world's largest vehicle market has many worried about a significant slowdown in the Chinese economy, and the wallets of a population of more than 1 billion. Last year, uncertainty about the fallout from the U.S.-China trade war and Beijing's efforts to reduce reliance on debt for growth put a chill on spending, especially on big-ticket items such as cars.

Much of the decline in auto sales in the last two years was the result of a tough comparison with rapid growth in 2016, Alan Kang, Shanghai-based senior market analyst at LMC Automotive, said on Tuesday. He noted a major drop came from decreased demand from China's smallest cities for domestic auto brands, while premium foreign brands had less of an impact.