Did this a while back and posted it elsewhere, so might seem familiar to some of you. Was a weather resistant / reversible solution to running a reasonably thick bundle of wires into the engine bay. Utilises the largest of the existing plastic grommets, the center of which is cut out so as the groove created will accomodate the new rubber insert. Piccies are of different views / stages and hopefully self explanatory - the additional grommet is a generic one and generally available, however I got this particular one here (no connection to them). https://www.stmotorsport.net/product-page/bulk-head-panel-wiring-harness-grommet-rubber-seal The last image is of it in-situ...
Nice. I think that's an updated version of an old Lucas electrics 2 inch standard wiring loom grommet.
Don't have one to know what can and can't be done, but maybe an opportunity for someone to 3D print the plastic part / prefit the rubber grommet, rather than people cannibalizing the original VW one?
Maybe someone with a printer could let us know, the original VW grommet is made of that semi-flexible plastic, so no issue with a bit of pressure. If 3D'ing is only capable of rigid items, could improvise and have an inside and outside ring that clip together through the bulkhead?
couldnt you just use the LHD engine/lighting loom holes tucked in the corner just above the chassis leg?
Likely plenty of other solutions, the wires I was running combined to make quite a bulky loom and any of the other grommets would've been a tight fit / risked chaffing. You can also get at the larger one quite easily from the inside if you're blind feeding wiring through. The inner rubber piece will hopefully stop moisture and fumes because of that tubed collar, not done in the photo but you can cable tie it if needed.
As I found when replacing the bulkhead grommets with some off ebay. The quality of some is really crap/badly moulded as well as being made of different material - eg rigid like the original referred to in this post. Not good for providing an effective seal.
