As far as I know its not actually limited to Classics - the guy organising it has a MINI as well as quite a few Minis. The original idea last year was to fit 100 cars into his garden so it was really a logistical consideration as it is a big garden but not that big!
I'm sure if you ring Michael and ask him he might allow the odd MINI to sneak in the back.....
I was at last year's and it was a great fun day - there's some pictures here:
http://www.mlni.co.uk/forums/index.php?showtopic=2263
Again, it would be a long trek from Cork but apparently the camping the night before last year was quite entertaining.......
ol: