+1 for the two bucket method. Pretty simple and much nicer on paint.
OP might also research "clay barring" if they aren't familiar. Sometimes after washing you still have residue left on it and running a clay bar over the top (usually with soap as a lubricant) it can pick up a lot more.
OP might also research "clay barring" if they aren't familiar. Sometimes after washing you still have residue left on it and running a clay bar over the top (usually with soap as a lubricant) it can pick up a lot more.