Save and invest in some nice wheels, tires, spacers and lowering springs (like VWR). It's your car, but personally these were on top of my list during the first 6 months of driving. Also, if you like to rub on her sometimes... watch some of the pro's on youtube detail cars and learn. Can save major bucks doing everything yourself (a buddy helps).
Congrats on your GTI, mine just hit 4400 miles and I love this car. I already have done what I mentioned earlier plus the jb4/down-pipe/vibrant resonator/IE Intake (for noises). I know drive the windiest roads I can find, the daily commute is now fun.