If you want to try a track day but want to keep it sensible, try www.mgs-on-track.com
These guys are an off shoot of the MG Car Club ( you don't have to be a MGCC member ) and they are run not for profit. This means no temptation to cram loads of cars on track to make money.
It's all MGs, it's all very sensible but that doesn't mean boring. I've done Brands and Silverstone GP and Donnington in October and each time I book instruction.
Must admit to being a bit apprehensive for my first visit, but they also have a buddy system to make sure a newbie has someone to shadow them as much or little as they want.
It's great fun, the only downside of spending the entire day between 5000 rpm and the redline is fuel consumption - 16 mpg last time