Just been looking on the Courtney site and they list the different upgrades.
So what happends if you work your way up the grades? It looks like you get charged for doing the airbox each time.
Also if you allready have the bigger 9 litre intercooler and modded air box how would they decide on the price?
Astra and Zafira Turbo Tuning Packages
CS1 Software Upgrade. This upgrade is designed for vehicles that are running full "OE" exhaust and standard intercooler set up.
All CS 1 upgrades now include a £300 discount voucher off any future CS upgrade on Astra and Zafira Turbo applications (valid for 12 months from date of CS 1 upgrade.)
Increases up to 224 bhp £599 Fitted
CS2 Software upgrade and airbox modifications
Increases up to 240 bhp £695 Fitted
CS 3 Software, airbox modifications, High Flow 9 litre Side Mounted Intercooler
Increases up to 250 bhp £1,199 Fitted