A couple of years ago, my friend got me to ring another of her friends and pretend to be the local Fiat garage. They had been waiting for delivery of their new car for ages, and I told them it had arrived, but Fiat had sent a bright yellow car rather than the black one they ordered, and "would this be a problem?". She went absolutely mad, slammed the phone down, then rang her husband ) we were meanwhile desperately trying to call her back). He rang the Fiat garage and gave them a blasting. He was not impresed when he found out the truth - neither were the Fiat garage! After that I have tried to steer clear of April Fools jokes.