MB antifreeze or its commercial equivalent - Zerex G-05 - has a very carefully formulated hybrid organic corrosion inhibitor package. It is best to mix 50/50 with water.

Unless you're a chemist and know exactly what is any ANY coolant additive, I would avoid using such, just as you do not need and should avoid use of any additive to any proper specification automotive fluid.

Some coolant additives may have a place in race cars, which often, by the rules cannot run antifreeze, since spills on the track are tough to clean up.

Beyond that, most automotive additives have another name - "snake oil". If you use OE recommended fluids you don't need additives. PERIOD!!!

Duke