Hello everyone - my husband and I own a 2005 BMW Z4. We have an issue with antifreeze leaking, although it's not going on the floor so we're not sure where it's going. When we start the car it smokes from the exhaust but about 30 seconds, then clears up. My husband thinks it might be the head gaskette which as you know is an expensive fix. Has anyone else experienced this and do you have any advice/recommendations? Many thanks.