Have used the Halfrauds own brand 'matt black bumper paint' a number of times, with excellent results.
They also do a surface preparation spray to remove all the grease and crap, defo use that too.
In my experience the best method is to wash, clean with surface prep, lightly key with very fine wet n dry, clean again with surface prep, then spray. 2 or 3 very thin coats works well.
Gives a very nice 'OE' look finish and very durable.
