Retail Chevrolet owners with an in-vehicle OnStar 4G LTE Wi-Fi hotspot and AT&T wireless account can add unlimited data to their vehicle for $20 a month starting May 12.

Owners will be able to add unlimited data to their vehicle at an AT&T retail store or via AT&T’s website, according to General Motors. The unlimited data plan allows Chevrolet owners to utilize their OnStar 4G LTE Wi-Fi hotspot and access without worrying about paying overages. The plans don't apply to commercial or fleet accounts.

Chevrolet offered 4G LTE unlimited data plan for all customers in early March. In April, Chevrolet owners used 415% more data than in April 2016. Chevrolet has sold 3.5 million OnStar 4G LTE-connected vehicles since June 2014, according to the automaker.

The 4G LTE Wi-Fi hotspot is standard equipment on all new Chevrolet retail models along with the OnStar Basic Plan5, which also features remote vehicle access and the AtYourService marketplace via the myChevrolet mobile app among other features.