Not hidden but clean and simple is to run engine bay wires inside smooth pvc wiring sheath like i did. These wires power things like radiator fans headlights turn signals and other important things.

Properly Shaved And Tucked Engine Bay How To
How to hide wires in engine bay. Using the frame rails to run wires is a given. Easy diy how to. Mercedes used similar in my 85 300d for both wires and vacuum tubing. Easier to keep clean than split loom and looks slick. The best way to hide those ugly wires is to tuck them into the fenders. A quick look at replacing damaged or missing wiring harness sleeve or conduit in your engine bay.
Using a fuel line heater hose or aluminum tubing works great for hiding wires and vacuum lines. After relocating the battery to the trunk and making a custom wiring loom from scratch all the wires are now hidden behind the firewall and fenders. It is kind of like heat shrink but doesnt shrink. But you cant and in most cases you cant even hide those rubber filled lumps of steel or aluminum that mount it all into your bay. Every time you pull a wire or wires through a loom always pull a dummy wire or heavy fishing line in case you have a need to pull an extra wire at sometime. So before we clean the engine bay.
Look for pvc 105 as i recall made by alpha or spc. This generation vr6 engine has a lot of wiring and harnesses under the hood. Sometimes these cable looms get torn up by inattentive mechanics or just break. Unless youve got a 92 00 civic or 94 01 integra in which. Next up in the mk3 gti build we are stripping all the wiring from the engine bay.