While your getting used to the stock power save some money for some of the common faults with the GTT.
Depending if it was done before have a look at the tie rod ends and castor bushes. Depending on the Kms you may need to change the coilpacks most seem to start to die at about 60,000kms to 100,000 kms and make sure you get a good workshop to look over everything. No point throwing $$ at a car that won't handle it.