Just get yourself a cheap bike helmet. All helmet on the Irish market are to a bike safe standard" so any of them would do in a car as the won't see the impact they would from a bike fall.
Not sure ill have a look tomorrow i got a few for the lads the last track day we did and some of them were saying they were a small fit
I can bring it to the track you can have a lend of it for the day after that if you like it you can have it for 40 if you dont ill take it back hows about that