Roof lining size?

Hi there,

Have had to remove the roof lining from my golf as the sunroof was leaking and has resulted in rust at the side of the roof. Once this is fixed i will be looking to replace the headlining and am thinking of using a manx or german flag but need to know the size i would need. Just wondered if anyone had a new lining to hand and could measure it for me?

Cheers

Marc