C-Class W203 Model -
For:
The C-class is comfortable, refined and well built saloon with a touch of class
Against:
Problems with electronics/software are widespread. Unreliable auto gearboxes, failing alternators and knocking suspension are also problems.
The gearboxes are not bulletproof so check if the transmission is jerky or has a tendency to hang on to gears.
The car is basically fine, but you should keep an ear out for odd noises from the suspension.
Please bear in mind that if this car has been fully maintained by Mercedes-Benz then the software upgrades will have been done. But still check the transmission.