Just got out for the first time yesterday at Combe and first post on this forum. Really love the car and had a cracking day, it's my first Golf Mk5 I owned and it's a beast. Tuned by rtech with a Dyno plot from a few years back at 350bhp with a hybrid turbo. Had a strange problem with cooling system though.
After getting out on track for 10 laps or so with needle at bang on 90c all way round I pulled into paddock, parked it up, let it idle and water level light came on (didn't all way round track) . No sign of coolant on ground, no overheating on gauge, not steam but definitely no water in header tank.
Let it cool, topped it up, let it idle and all looked good so went out again. The same happened like 4 times (topped up about 3l in total).
We checked for leaks evertime, nothing. Wondered about head gasket but checked with one of those coloured co2 leak things, looked for mayo in oil cap, listened for misfire, checked exhaust smoke out on track. Nothing looked bad.
Car has stock rad and stock oil cooler...could it be part of problem? Dumping loads of heat from turbo when pull up after hot laps? Seems like a good idea to upgrade them anyway? Doesn't explain where water is going either!!!! Any ideas or had a similar thing?

