Not sure if they use the same type of radiators, but I know classically on the W124s, the radiators crack at the joint where the inlet hose from the water pump is attached. This is where 99% of the radiators fail, and usually at over 100K miles.
The upgraded OEM radiators are reinforced with a steel shim inside the plastic intake junction.
New ones are around $300, and the install is pretty straightforward, even for a DIY'er with basic skills.
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car