The first two events were April 5 and 6 at the new Texas Motor Speedway in Fort Worth.
Production Media clients Coca-Cola Co. and Sun Microsystems are expected to be among those using Megavision. Holiday Inn Worldwide is said to be finalizing a deal.
Production Media will have about four in each speedway.
This is Megavision's first foray into motorsports. The Panasonic-made boards this year hit the streets of New Orleans for Mardi Gras, delivering impressions for Coca-Cola and others.
In July, it will unveil a 200-foot-wide video board at the Atlanta Festival of Music & Multimedia.