Complex sentence: The Ginetta GT Supercup is a one-make racing series based in the United Kingdom, using identical Ginetta G50 and G55 sports cars and supports the British Touring Car Championship (BTCC).
Split into simpler sentences: The Ginetta GT Supercup is a one-make racing series based in the United Kingdom, using identical Ginetta G50 and G55 sports cars. It is a support series for the British Touring Car Championship (BTCC).