The unlimited prepaid data plan will be available for only $20 per month.

The ongoing 'unlimited' data battle among cellphone carriers has now reached the auto industry, with an unlimited data plan soon arriving for Chevrolet's OnStar Wi-Fi hotspot service.

Drivers will be able to sign up for unlimited prepaid data via AT&T's 4G LTE network for only $20 per month.

"We have contractors bidding jobs in their Silverados, families streaming movies in their Suburbans and Malibus and everyone tapping into the cloud for music," says Chevy head Alan Batey.

It is unclear if the plan carries the same restrictions as AT&T's 'unlimited' cellphone plan, which reduces tethering speeds after 10GB and disables HD video streaming by default.

General Motors suggests OnStar hotspot usage has exploded, increasing by nearly 200 percent from 2015 to 2016. Combined data usage last year has been compared to streaming more than 17.5 million hours of video.

The new plans roll out tomorrow for all supported vehicles in the Chevy lineup.