Mahmoud decides to buy a brand new car from Ahmed's garage. He places a written order for a car with an 1800cc engine, in the colour red, and he asks for it to be fitted with alloy wheels and a satellite navigation system as accessories. Mahmoud pays Ahmed a deposit of 600 and agrees to pay the balance of 11,400 upon delivery. Three weeks later, Mahmoud receives a telephone call from Ahmed to say that the car is ready for him to collect. When Mahmoud arrives to collect it, he discovers that the car that Ahmed has reserved for him is an 1800cc model, but is blue and has neither alloy wheels nor a satellite navigation system fitted. Mahmoud refuses to take delivery of the car and to pay the balance. With reference to decided case law, advise Mahmoud and Ahmed of their respective rights and liabilities as a consequence of these events.