Legally Register Any Car

This is a very interesting debate for me- I had no idea some states don't title older cars! I have to have a title in hand when I buy a car on the mainland to ship it, unless I am shipping it as parts. the bill of lading is needed, with title, to register the car in Hawaii. Pretty big annoying process actuallyh.
I'd bet most every state has a reciprocal agreement with states that do not title older cars. Most people just don't bother going to DMV to ask the question to in fact find out.