Head gasket and oil leak!!

[jibm]

Morning gents

I did a track day at Bedford on Monday and my water temp gauge was rising to near the red when at full throttle i backed off and made sure it didn't get too hot. After searching and reading on here it seems to point to the head gasket that could be the culprit. At the end of the day i also noticed and oil leak splashing down the NSF wheel arch and sill, although is not a massive leak and the oil level has not moved.

The car has warranty, however i am flapless and my concern is the warranty guys will notice this and reject it. The easy thing i hear you say is put it back in, but unfortunately the flap has gone missing during a house move and i cant find it anywhere!!

Thoughts gents please?