You need to have a game saved on mem' card. Select the two player option. Select High Stakes. Press X. It should come up with a message and two options. Select the OVERWRITE option. Selct your track. It will come up with a message saying "Checking for Valid Memory Card in slot 1". Make sure you have your mem' card in slot 1. The it will have another message saying "Checking for valid Memory Card in slot 2". Quickly remove the mem' card in slot 1 and insert it in slot 2. Select your car(s). Put your mem' card in slot 1 to load the 1st car, Then switch it over again.

Make sure that the 2nd player Forfeits.
Make sure that your memory card is in slot 1 to receive your cloned car.