2cats dumped

About 2 weeks ago one of the ladys at work watched a car take off from behind the store.It left behind 2 cats .This was before thanksgiving ,i saw one of the "cats" last night and im thinking the black and white i saw was maby 3 to 4 mths old .The calico I havent seen yet but im thinking mom ?Or it could be a sister . Im taking a live trap over today (i know the one is living in our greenhouse)Im thinking because they were in someones car they were pets, but how long does it take for them to go a little wild .i think it goes cat by cat and know they will take some work but one or both (if they can be traped)will come home with me. Feel bad about not traping sooner,Please dont make me feel worse