I need to get three sheets of 1/2" plywood home from Home Depot. If I ratchet strap them to the top of my mazda 5 and take it slow (like 30mph tops) will that work?

I really do not want to have to get a truck. it's like 2 miles away from my house

@csalzman I would tie them front-to-back also. Or at least front-to-strap. You want to keep them from flexing upward. Drive very slowly.