* Elliott, others say plan detrimental to minority shareholders (Add comments from Vice Chairman ES Chung, experts): SEOUL (Reuters) - South Korea’s Hyundai Motor Group has shelved a restructuring plan which would have given the son of its aging chairman more control of the conglomerate, following opposition from investors including U.S. hedge fund Elliott Management Corp. The decision is a rare victory for an activist shareholder in South Korea, and comes at a time of growing public scrutiny of families controlling large conglomerates following a corruption scandal last year involving the Samsung Group.