I can confirm DrDeville's post. My 300C began "waking up" around 1000 miles and at 1500 miles finally seems to "roar". Now that the engine is alive, I really need to get new tires, these CONTI's just plain suck.
My current bogey is Michelin Pilot Sport A/S 245/45-18.
245's are the widest I've found recommended for the
stock rim width (7.5"), and the Sport A/S's offer excellent
wet/dry handling and better tread life than a summer
performance tire like the Pilot Sport. At around $250, they
are pricey, but at least should last a while. And they
will perform better and cost less than larger wheels of
the same weight. If you are looking for a smidge more sport,
they might be a good choice.
George "Dreams Available, Reasonable Rates" Ferguson
On the Brampton board someone asked about the computer limiting power etc during break in. The folks from the factory said that there are no computer controlled limiters that detune the engine or limit performance. Just use common sense and RTFM (Read the fine manual) about what the factory recommends.