As Will said, when we went three weeks ago, (we were on track with the BMW not the zeds) the first 2/3 hours was mayhem. Car being transported back to the pits with various bits missing or hanging off.
This would be great track to drive if less cars out on circuit at a time.
The zed will handle Cadwell very well, but you will have to be more watchful of other cars on track than most circuits.
Hope you have a good track day.
Do mods before you go for a remap, and you will have to spend a few pounds .
Remap alone will cost you £400.00+, but after that you may not get +30bhp, each zed is different for gains.
To many cars on track, more than i have seen on previous track day events.
I would not take the zed on cadwell either, as Will said, to many incidents.
Mind you, i did let Andrew loose with my daughter