I live in michigan and have 2 late model cars that need collision and 1 car that doesn't. who's the cheapest?

Pick up the yellow pages and call around.

I go on line and search for quotes and also call the insurance company's in the phone book, then you will get a good idea.
Know what you want so they can give you a quote or call you back.......xx

There's no one size fits all cheapest. Some are better with youthful operators, some not. Some are better with lower credit scores than others.

There's no short cut, to find the lowest rate for YOUR situation, you need to shop around to several agents - including at least one independent agent, who can get you quotes to several companies.