Ask HN: What AI tool can watch the market of used cars for ones of interest?

I'm in the market for a used car of a certain make/model with a particular set of features. This particular combination infrequently arrives on the market via lease returns at dealers, and sometimes on other marketplaces. Buying one requires identifying candidates quickly. Searching for these manually is time-consuming, and doing it daily is even more so.

What tool could I use to build an AI agent that can essentially watch these websites for new inventory becoming available, searching the listing or Monroney sticker for features of interest, and then sending daily notifications of any cars that fit the criteria?