The four S's: Sale (整车销售), Spare parts (零配件), Service (售后服务), Survey (信息反馈). The model arrived in China around 1998 with Guangzhou Honda and is now standard for any official-brand car dealership.
usage
Read aloud as 'four S diàn' — say the digit 4 in Mandarin (sì) and the letter S in English. Pure-letter brand abbreviations (KTV, ATM, X光) follow the same letter-as-English convention in spoken Chinese.