Brake shudder
 

I have just (4 days ago) bought a 2006 Cayman S with 42K miles and 1 lady owner. The car looks very clean but braking from 70+ mph causes steering wheel to shake and brake pedal to pulse. :(

The car was bought from an independant dealer who said it had neew pads on refurbished discs and the pads would take to time to settle in. The discs were apparently cleaned up to remove light rust but not milled. I've now done 400 miles and the preoblems persists. Any suggestions?
- Warped discs?
- Unbalanced wheels?
- Faulty ABS?

Many thanks for any advice

Nige22