I have got my old superb 2 back after giving it to my dad a few years ago. It's a great car and I'm tempted to keep it but the 18" wheels with the 40 profile tyres are ridiculous. 

I have heard that 45s will work but has anyone tried 50? I might just need to find 16" wheels...

Currently have a mk2 superb on my winter wheels (16 inch) definitely helps with absorbing the bumps, but the car does not feel as positive, on the 18 inch wheels with the 40 profile tyres it feels like it is on rails

Have a read here:

https://www.briskoda.net/forums/topic/445067-superb-2-wheel-and-tyre-information/

Perfect thanks for that