Dealer can't find coolant leak. Wife won't drive it anymore

[nordic]

Hi

I have had a tiny coolant leak for 2-3 years, a top up every 4 months or so, recent its more, lot more, every week or so, a small top up is needed.

I had the car at an Indy garage last week to change discs/pads and too look for the coolant leak, they did a pressure test and he could not find it.

Car into dealer today for normal long life service and asked them to find it too, as somehow i thought they would..expecting a massive bill , but got a call saying they could not find a leak, they also pressure tested it.

So, no water in oil and the car does not give out any white smoke.

I don't feel like telling the dealer to look more into it yet as cant afford a massive bill from them.

Wife now thinks the car is unreliable as she panics when the coolant alarm goes, is it time to sell the car and get a B7 or does anyone have any ideas where to look for the leak ?

Thanks for any advice !