Well, that was some fast construction. In-N-Out Burger opened at 3701 S. Lamar Blvd. this morning in the old Wendy’s space. It is the fourth Austin-area location for the California-based burger chain. The restaurant features double drive-thrus and is open Sunday-Thursday from 10:30 a.m. to 1 a.m. and until 1:30 a.m. on Friday and Saturday.