As for a Cayenne Turbo (non power pack) vs....
vs. M3, no competition there, the M3 will whoop the CTs ass anyday. No CSL needed. The engine response of the CT is glacial compared to the N/A M3, with noticable turbo lag. Of course, the M3 must be in an appropriate gear!
vs. 530d, on the first half of the speedo, ie. till 150km/h, the 530d aquits itself suprisingly well! Esp from 0-50/60km/h (ie. city traffic), the 530d just romps away from the CT! All that torque and instant response! But of course, once the CT gets into its stride...