Got in the car to go home from work this evening and no more than 2 minutes up the road the car started beeping and the red water temp warning light flashing. The temp needle hadn't moved at this point, stopped the car, engine off and started back up. No warning all the way home (about 10 mins) temp seemed to go up to about 75 pretty quick though although I don't confess to knowing actually how quick it's should get up to temp it usually seems to take longer. Anyway I got home lifted the bonnet half expecting to see an empty reservoir but as far as I can tell in the dark its well above min level but it looks crystal clear which doesn't seem right. Anyone advise? 

Turns out that in the cold light of day its not the bottom of the coolant bottle I could see but the reflection of the top and the coolant isn't clear but black. Fingers crossed its the oil cooler and not the head gasket. 

I have the same problem.

You may find the below link useful.

http://www.vwaudiforum.co.uk/forum/showthread.php/28826-Coolant-Temp-Level-light-Flashing

 

Cheers

Think it's bit more serious than the sensor now (see my second post). 

Yes sorry.......did not clock that.

Good luck with resolving