Do it jimmy, do it!
Get rid of the run flats and chip the b!tch, they chip to about 360bhp with a lovely straight biturbo power curve. Rear wheel drive go on son do it!
You will have to treat the throttle with respect or it will send you into a delightfull power slide. It's not as "fun" as the gti if that's what you like but way more driver focused and serious. Proper car you'll love it.
Oh and test drive the harmon kardon wireless, it's the bomb in a 3 series.