For really top job use 3m trizak disc p3000 grade on a D.A with soapy water. Use 3m fast cut compound (green top) for polishing.For dark colours use blue top. Use these with a hard compound mop. Finish off with a soft finishing mop useing 3m finnesse it or machine glaze.
G3 is ok if the above can't be sourced

Regards
Jim