The part nobody cleans.

Done properly, yes. The work is in the preparation: covering the alternator, fuse box, intake and any exposed electrical connections before anything wet goes near them, and using controlled amounts of water rather than a pressure washer across the bay.

Two reasons. It is one of the first places a buyer or mechanic looks, so a clean bay reads as a car that has been maintained. And with the grime off, fresh oil or coolant leaks are actually visible instead of hidden under years of build-up.

It is quoted on the vehicle, because how long a bay takes depends entirely on how much build-up is in there and how tight the engine bay is. It is commonly added to a full detail rather than booked on its own.

We would rather do them at the Nerang studio. Engine bay work produces run-off that needs somewhere appropriate to go, which a customer driveway usually is not.