A Bethel-based performance car company is looking to expand operations with a new facility that would double its space and significantly grow its workforce. EFI Performance plans to move from its current six-thousand square foot garage to a new twelve-thousand square foot building in the Berkshire Industrial Park near the Danbury border. The project has already received construction approval, with final review focused on how the building will be used. If approved, the company expects to increase staffing from about ten employees to as many as thirty, with space for vehicle tuning, repairs, retail, and a specialized testing area to measure engine performance. A public hearing on the proposal is scheduled for May 12.