I am surprised you beat modded GTO's but I am sure the elevation has a lot to do with it. I have driven a procede 335i as well as a modded GTO. Exhaust, and intake and the GTO felt faster. The GTO is my cousins car but I think it felt faster because of the torque and the sound. It is very hard to launch the car with the skinny tires. The car wont even fir a 265 tire on the rear. Imagine trying to get 375-385 whp (which his dynoed at) on a 245 tire. There are 325i and xi with wider tires in the rear than that. GTO is a steal for the money and the interior looks way better than a mustang any most other muscle cars. If everyone here drove a GTO they would understand. The car is a BEAST trust me. I drive 335i just about everyday because I sell them so I have a good idea or the differences. The race is truly a drivers mainly because the GTO is hampered by tire width. My cousin has the 6.0 BTW with a corsa exhaust and it sounds sick.
2010 AW e90 328i: 6 speed, Black Leather, Dark Wood trim, ZPP, ZCW, ZVP,ZSP, Nav, Xenon
BMW Performance CF Rear spolier and Gloss black grills
2008 Candy White MKV GTI 2.0T 6 Speed Manul Gone
2008 AW X3 3.0si: 6 speed Returned
2006 AW e90 330i: 6 speed Dinan Stage 1 Returned