Tire Rec for '2008 CLS63 w/ Performance Pkg'

The Continental 285/30 ZR19 98Ys do not seem to be able to handle the torque--frequent sliding on acceleration.  Dealer says plenty of tred still left on the tires, but when I drive they feel very slippery.  Can anyone recommend a brand/spec for a rear tire which is better suited for this car?  Thank you in advance for any help you can offer..