Sisters 2013 Jetta Sportwagen 2.5 coolant light came on when I was visiting. Stopped at parts place in her town that had Yellow supposedly good for all colors. Adding about a pint solved warning light problem. checked VW Owner Manual that said use VW pink Fluid. Now that I am home I discovered that the VW fluid is life time and does not need to be changed periodically. Saw that Peak Purple is for Euro cars. Will a pint of Yellow for all colors cause problems?