BERLIN—Elon Musk was cheered as he oversaw the handover of Tesla’s first German-made cars at its Gruenheide plant on Tuesday, marking the start of the U.S. automaker’s inaugural European hub just two years after it was first announced. Loud music played as 30 clients and their families got a first glimpse of their shining new vehicles through a glitzy, neon-lit Tesla-branded tunnel, clapping and cheering as Tesla Chief Executive Musk danced and joked with fans. “This is a great day for the factory,” Musk said, describing it as “another step in the direction of a sustainable future”. Musk said that Tesla is likely to launch a test version of its new “Full Self-Driving” software in Europe, possibly next year depending on regulatory approval. “It’s quite difficult to do full self-driving in Europe,” he told factory workers on Tuesday, saying much work needs to be done to handle tricky driving situations …