Strange one this... the water temp and the oil temp are both reading about 20 degrees cooler than normal. First thing I did was change the thermostat because I thought it might be stuck, but that didn't make any difference. So I put it on VAG-COM while it was running, and the temperatures reported actually looked normal on the computer, but the gauges on the dash are still reading about 20 degrees too low! So basically, the engine seems fine, fan cuts in at the right temp etc, but the gauges are wrong. What on earth could cause this?