Wiktionary
carriage trade
n. 1 Retail business with wealthy or upper-class customers, i.e. those who arrive in carriages 2 Wealthy or upper-class people in general
WordNet
carriage trade
n. trade from upper-class customers
Usage examples of "carriage trade".
I get it from the law, I get it from the hoodlum element, I get it from the carriage trade.