Roadster

• 1). Pull back the carpet on the bottom of the trunk to reveal the engine hatch.
  
  
• 2). Take the cap off the water cooler thank and and pour in your coolant. There's a mark on the side of the water tank designating the maximum amount of coolant you should pour in.
  
  
• 3). Replace the cap, engine hatch and carpet.
  
  

Fortwo

• 1). Remove the plastic grille below the front windscreen on the right hand side of your car.
  
  
• 2). Push the tab at the top of the unit and pull it out to reveal the coolant tank.
  
  
• 3). Remove the cap from the tank and fill it with coolant to just below the plastic indent toward the top.
  
  

Smart 999cc

• 1). Open the hood and remove the coolant cap.
  
  
• 2). Fill the tank to the highest marker on the side.
  
  
• 3). Replace the cap and close the hood.