God! The student grant system in Australia must be good. Students here can't even afford gears on their push bikes never mind brand new BMWs.
Anyway. I know I've got the d but I test drove a 125i. It was very good but as others have said, it doesn't make much noise. I had a 3.0 z4 just before the f20 so similar engine to that in the older 135i in that it has the correct number of cylinders. The noise of a BMW straight 6 is simply sublime. You would enjoy the 135i but you would feel slightly down about the dated equipment and interior every time you saw an f20. Where as if you bought the f20 you'd nearly always lust after a straight 6 howl. I suppose you could improve it somewhat with an exhaust and filter.
Daily Golf R
Project Peugeot 205 1.6 GTi