Engine bay advice

[Niiick]

I've been looking at the way Derin prepares and presents his BMWs in the general chat forum and now feel suitably ashamed by the state of the engine bay in my 325i.

Twice now I have used a paint brush and Gunk followed by a rinse off with normal hose pressure, but it still looks grubby and dull. There is still a considerable amount of the original varnish left everywhere and this acts as a perfect trap for dust and grime.
I'm going to order eight of the steel clips that hold the grill sections to the bodywork, as the existing ones are corroded and look tatty.

Can anyone advise how to remove this varnish stuff BMW cover the engine bay with when the cars are new? I've resisted the temptation of using a pressure washer, but it may be that is required?

A picture of the filthy badness -

(and no sniggering at my horn please)

[oakey]

For the "varnish" some sticky stuff remover should do the job. For all the plastic/rubber parts use something like flash wipes. And Gunk with a stiff brush for the metal greasy bits. No need for a jet wash imo.