Update: trace bullet is right. No heat needed. It is actually better if there is no heat because the sticky part is going to stick on the vinyl and not on the car. No residue would be left behind once you remove it. It's like peeling off a sticker out of your car. Currently removing the roof stripes as I type this and yes, 0% residue left, but still have to use goo gone 'cause of the edges. I think water will do.
Note: For the hood. Allow your car to cool down so the hood and the vinyl won't be too hot. Otherwise, there is a high chance that a residue will remain on the car and I swear, learned by experience, that residue is going to be hard to remove even with the use of goo gone. Will post pics in a bit.