Gurugram-based used cars buying platform Cars24 has raised $100 million in Series D funding round led by Unbound and KCK Global, who invested $25 million each. Telecom tycoon Sunil Bharti Mittal's son Shravin Bharti Mittal invested in the round through his London-based investment firm Unbound. Moore Strategic Ventures and existing investors, Sequoia Capital and DST Global, also participated.