SAN FRANCISCO—Electric carmaker Tesla will make a “dedicated” self-driving taxi that will “look futuristic,” Chief Executive Elon Musk said on Thursday, without giving a timeframe. The 50-year-old billionaire, wearing a black cowboy hat and sunglasses, made the comments at the opening of Tesla’s $1.1 billion factory in Texas, which is home to its new headquarters. “Massive scale. Full self-driving. There’s going to be a dedicated robotaxi,” Musk told a large crowd at the factory. Musk has several times missed his targets of full autonomy. In 2019, he said robotaxis with no human drivers would be available in some U.S. markets in 2020. In January he said he would be “shocked” if Tesla did not achieve full self-driving that is safer than that of humans this year. Tesla will expand its “Full Self-Driving” beta software to all North American FSD subscribers this year, he said on Thursday. Tesla now sells the …