Volkswagen Bora - Rev Fault? - yazzers09

hi my partner just bought an Xreg Volkswagen Bora 2Litre Petrol, when the car is on tick over, the revs go up and down, but as soon as it hits temperture its ok? is this normal and if not, what shall he do please?
Also, i'd like to know what common faults they have,

Many thanks Yaz

Volkswagen Bora - Rev Fault? - Avant

Moved to Technical.