As above Oil, Oil filter, Gearbox oil, Pollen filter and Drive belt Any decent brand 5w30 fully synthetic oil. The OEM denso oil filter is the best for the 2zz Brakes: MTEC drilled and grooved are a firm favourite (as said above) Induction kit: The pipercross viper kit seems to be the trend at the moment, requires a small amount of custom work to make full use of the cold air feed Lowering Springs: TTE/Eibach, Apex and H&R are recommended. Definitely a must on the Pre Facelift T Sports Rear Anti Roll Bar: Probably the best modification for the CTS, really sharpens up the handling especially when combined with a good set of springs. Progress and Whiteline produce good quality bars Front Strut: All the same really, you will need to bend a brakeline in order to make one fit on a Pre Facelift car I have done all the above bar the brakes and my car goes and sounds brilliantly, the handling was vastly improved by adding the springs, front strut and rear arb