Whilst driving a few days ago I noticed that cold air was coming through the heater vents, in spite of the car being up to normal operating levels. During this drive and any other subsequent drives that day, I noticed that the heater appeared to have a mind of its own; one minute hot air, the next cold air. The same symptoms were evident yesterday. Today though, things appear to have got worse. Apart from the above mentioned problem, I have noticed that the temp gauge is fluctuating wildly from