Tesla Inc. started summoning non-employee Model 3 reservation holders to configure their cars, a sign of progress for the sedan plagued by production problems.

A Tesla spokesman said in a text message Tuesday that the company began sending invitations to depositors outside the company’s employee base to design the Model 3. The car starts at $35,000 before options or incentives and is pivotal to Chief Executive Officer Elon Musk’s attempt to transition Tesla from a niche player to high-volume automaker.

Model 3 production has been undercut by bottlenecks both at Tesla’s assembly plant in California and its battery factory in Nevada. In the third quarter, the company built only 260 of the cars, far less than its 1,500-unit forecast. Initial deliveries have gone to Tesla employees, investors and close friends of the company.

The Model 3 Owners Club, an online forum, tweeted Tuesday that one of its members, a current Tesla owner who is not an employee, was invited to configure his vehicle and was told delivery would take about four weeks.

This article was provided by Bloomberg News.