I am at the point of installing the decks on my Sassafras 12.  I will be putting this on top of my car for both short and long (highway) trips.  Should I add padeyes on the decks, with a backer block for the screws (or bolts) to grab or add a cleat underneath the deck secured to the inwales that the padeye can be screwed into through the deck, to tie off the bow and stern while on the car?  Or, is there a better way to plan to secure the boat especially for longer trips at highway speeds?  Are there car top carriers that can safely haul this boat without tying off the ends?  It seems most that I have seen recommend or require securing the ends especially for higher speeds.