A marketing company is on a roll with a truck poking fun at Anthony Weiner’s serial sexting issues. The company — which, for a fee, encases one or both of its two trucks in plastic wrap displaying commercial advertisers’ messages — has been rolling this vehicle out in Union Square lately to showcase its services. Representatives say the “Weiner Truck,” which has been giving out free wieners, as in, hot dogs, has been getting a rise out of passersby. Currently, the company’s other truck is sheathed in Poland Spring advertising.