I get that the rule-of-thumb for talking to cops is that you should have a lawyer present. But like, what if it's small shit? Hypothetically, what if I witness a hit and run and the cop is asking me what I saw? Should I really insist that I have a lawyer present?

Sorry if this question sounds really dumb, but I've always been playing this situation out in my mind. My feeling has always just to say what I saw, like tell the cop "it was a grey Mazda SUV". Should I tell the cop that I'll make a statement in the station with my lawyer present?

Also what if there's currently a crime in progress, like a shooting or something? I guess that's unlikely, and that cops are useless.