CLK 55 AMG oil coolers

[2skiddy]

Hi, I have read somewhere that there have been problems with the integral radiator transmission coolers on these cars. Is this true and how can it be avoided. What about a separate cooler? I know it won`t then heat the trans oil, this could be bad? Also has anyone added an engine oil cooler instead of the little heat exchanger? My car is the 209 and will be used for track days.