As title suggests, I have a coolant loss, there is no smell inside the car, checked under the bonnet, no leaks there. Have no idea what it could be?

Thanks

Hi, if there's nothing evident in the car or from the engine bay (it's worth checking quite carefully as a minor leak may not be readily noticeable) then may want to think HG. Is there any evidence of water in the oil or emulsification forming under the oil cap?

You dont say what year your car is but I had a coolant loss issue on my 1.8TSi a couple of yeas ago but it was only when i drove it hard.

Turned out to be one of the lower rad hoses/pipes.

^ Have had similar when system under increased pressure & equally difficult to detect

if you can smell the coolant inside the car it's likely to be the heater matrix