Hooper specialized in the very top tier of the market, building the most luxurious bodies possible without consideration of cost. The models were not sporty, as the company specialized in stately, elegant carriages. Coach customers included the Marquis of Londonderry and the Marquis of Crewe . Car body customers included the Kings of Spain, Norway, Portugal and Siam, the Shah of Persia and the Negus of Abyssinia. In 1911, Hooper built an extension onto their Kings Road works, due to increased customer demand. Their London showroom, opened 1896 (possibly earlier), was on the corner of St James' Street and Bennet Street. It included a vehicle lift so that coaches and cars could be displayed at first floor. The alterations are likely to have been overseen by Francis Hooper, architect, son of the then owner.