Brakeleen / degreaser for any oily bits first ... the rest is rag(s) + tooth brush, half a day with meguiars tar and bug remover.
Works really well on metals and kind on paint.
Two show and shines with placings + a magazine shoot agree ... it works (all different cars)
Water and engines is a bit of a no no. Too easy to screw and altenator or other parts.