For those that are attending on Sunday, I think that the best option would be to go straight to the event, just follow signs for Classic Car Show when you arrive at Hardwick Hall entrance,
https://www.google.co.uk/maps/@54.65...7i13312!8i6656
and you will then go round the back of Hardwick Hall, and onto the show field, next to the Hotel.
and you will need your ticket as you enter the show field, just tell them you are on the rover 75 and MG ZT Club Stand
Show starts at 1000 hrs, so would recommend getting there at no later than around 0930 hrs, to avoid any queue's
Stu