I must stress only MB coolant, get it at the dealer.
Mine was around $13 a quart and in the scope of the cost of ownership the cost does not make that big of a difference.
It is orange and is the ONLY COOLANT APPROVED FOR YOUR VEHICLE
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record