The falcon wing doors are a signature feature of the Model X, which has a base price of about $81,000.
According to the lawsuit, Hoerbiger is seeking additional payments from Tesla for the work it says it was promised. Tesla disputes that it owes the company anything more than the $3 million it paid for prototype parts and engineering.
Tesla delayed the Model X several times. It was first supposed to be produced in late 2013. In late 2014, Tesla said the vehicle would debut in the first half of 2015, but again it was delayed until late in 2015, except a handful of vehicles that went to company executives and early investors.