We don’t recommend tying a mattress to the roof of your car when moving. Not only can this damage your mattress, but it can also damage your car. It’s only feasible if you have a roof rack, and even then, you need to seal your mattress in a mattress bag to protect it from the elements. You also need to make sure you can still see your surroundings clearly. If your mattress is not properly secured to the roof of your car or it appears to be blocking your front or back views, you may be pulled over by authorities.