Head Gasket MG ZR

[Scottdog]

Hi

Recently bought the car from a dealer and it had a 3 month warranty.

I took it to a garage who said the head gasket had gone, although I couldnt tell until I inspected the engine with their help. Gunk in the coolant etc.

Anyway, the dealer has agreed to put a new one in.

However, my question is : How reliable are replacements? I love the car but should I try for my money back?

Any advice would be appreciated