A giant piece of street art has appeared in Cardiff city centre this week. Sully’s café on Quay Street has been transformed with the creation of a 30ft graffiti mural to celebrate the 2019 Adrian Flux British FIM Speedway Grand Prix (SGP) returning to Cardiff this September for the 19th year. Created by Prime Mural Arts, the dynamic street art took 72 hours and over 100 cans of aerosol to complete. Depicting two Speedway riders – current champion and British…