SummaryCompaniesTesla accounted for 38% of August US EV salesIts July US market share down most since March 2021Rivals launch new vehicles, offer steep incentivesSAN FRANCISCO, Sept 8 (Reuters) - Tesla's (TSLA.O), opens new tab U.S. market share dropped to a near eight-year low in August as buyers chose electric vehicles from a growing stable of rivals over the aging lineup offered by CEO Elon Musk's company, according to data from research firm Cox Automotive shared exclusively with Reuters.The...