GitEmSteveDave made a magnetic Starbucks paper cup to attach to the roof of his car.
He drives around and tweets peoples’ reactions. Sample tweet: “13 honks, 3 points, 2 mimes, 3 StopLightTells, 1 flash, 1 wave, 2 laughs, 5 AlongSideRiders, 4 2xTakes, & 1 cute girl took my picture.”
He shares how he made the cup on Instructables.
How to make a roof coffee cup.