(Bloomberg) -- Sono Group NV will abandon its Sion solar-electric car and slash most of its workforce after failing to raise enough money for the costly project.

The German startup said Friday it will dismiss around 300 employees — some 73% of the total — and shift its focus to selling technology to other companies. The Sion, a boxy hatchback covered in solar cells for charging on the go, was due to go into production this year.

Sonos fell as much as 27% in New York, the steepest intraday plunge on record. The stock declined 23% to 65 cents as of 10:01 a.m. local time, a far cry from the $38.20 peak closing price the day of its November 2021 debut.

“It was a difficult decision,” Chief Executive Officer Laurin Hahn said in a statement. “We were compelled to react to the ongoing financial market instability and streamline our business.”

The Sion’s demise is the latest in a string of disappointments for companies trying to develop solar cars. Dutch startup Lightyear suspended production of its €250,000 ($264,450) debut model and went bankrupt last month, though it announced plans earlier this week to set up a new company. California-based Aptera Motors meanwhile has struggled with a crowd-funding campaign to commercialize its three-wheeled vehicle.

Sono similarly had difficulty securing enough financing in the years before its New York listing. The Munich-based company says it had more than 45,000 reservations and pre-orders for the Sion and will try to sell the program.

Read more: Solar-Car Maker Skirts Insolvency by Seizing On EV Stock Frenzy

Sono plans to retrofit third-party vehicles with its solar technology and counts Volkswagen AG’s Scania and MAN Truck & Bus among its customers. It’s been touting a kit to outfit combustion-engine buses with solar panels to save diesel fuel.

(Updates with shares in third paragraph.)

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