Road Hog Birthday Cake

I was commissioned to make this cake for my customer's son. He had been learning to drive and she loves pigs so she requested a Mini Cooper convertible car with the little pig as her son (complete with headphones - he's rarely seen without them) and Mum and Dad in the back. The cake base is a chocolate fudge cake. The finished cake measures approx 7 inches (18 cm) wide by 10 inches (25 cm) long.