There is a vendor on this board that sells slotted rotors. Just do a search for slotted rotors. He had a black friday sale, but I forgot the name of the co.

 

I was having a high speed vibration especially with heavy brake pedal pressure and replaced my stock rotors with Sebro slotted rotors on all four corners. They weigh the same as stock (a lot) but they cost less and are a great replacement because they won't crack like stockers will. I paired them with cool-carbon pads and the whole job cost me less than $900 from Pelican. Cool carbon has great bedding in instructions on their site also.
I only do a few track days a year but my stock rotors were really taking away a lot of the enjoyment once they started shaking violently at the end of every straight.
As a bonus, these cars probably have the easiest brakes to change of any I have ever worked once you've ditched the dampening spiders that protrude inside the caliper pots.

 

Thanks mrmaass!

 

I have cryo treated slotted rotors on my Audis and like them. I believe they are stoptech.