This was in the G-Spot sub-forum, useful info so linking it here:

https://g35driver.com/forums/g-spot/...my-brakes.html

 

Thanks man that should help a lot of ppl like me... anyways will be careful from now on as i have not incurred any damage yet and i do let the brakes cool off for about 5mins+

 

I found this:

http://www.cartalk.com/content/puzzl...02/answer.html

Apparently the difference between washing hot rotors and driving through a puddle is that the puddle gets both sides of the rotor wet and equalizes the cooling.

Washing the brakes only wets one side and...... WARP.

 

30 sec is way too soon to be spashing cold pressurized water onto a rotor. What's the particualar rush anyway? If anything, do the wheels last. By the time you do the rest of the car, the rotors will have cooled to a safer temp via time and some incidental rinse water.