What is this bump for on rear panel?

[G69]

1972 and earlier cars do not have it.

[moito]

have seen some cars that had a switch for the alarm system mounted there...
but not sure if this was already an option for 73-

[Eminence Gris]

I asked the same question a few months ago and just got someone's attempt at humor.

It is not on early 73s. It is roughly the timing (around April 73) of the introduction of the externally-sealed mainshaft version of the 915. And it continues thereafter.

The logical thing is an alarm switch - or engine compartment light switch - but I've never seen either use that spot.

[jameshtaylor]

My 73, built April--June 1973 had it. No idea about its function.

[PMNorris]

That is a G series rear panel. F series cars didn't have it. I think its where the engine bay light switch presses against, which is mounted on the engine lid.
Paul

[Eminence Gris]

That is a G series rear panel. F series cars didn't have it. I think its where the engine bay light switch presses against, which is mounted on the engine lid.
Paul

I think you will find there are many thousands of F series cars with that 'bump.'

[PMNorris]

That's interesting. My Karmann built, German delivered 70T has the bump, but i was told that only G series cars had the bump, and mine shouldn't have it. I was told this by a restoration expert in Nurnberg, Germany when i had some work done on it. He assumed the car had been rebuilt at some point in the past. This is pretty much a certainty as it is 100% rust free, but i have not details of the rebuild. Anyway, it would be good to get a definitive answer on the mystery bump!

[Eminence Gris]

I was once proudly shown an "original paint, unmolested" 66 912 by a proud seller... And pointed out the bump. Oops.

[Schiefer]

Original 72S, no bump:



Low mile 73T, bump:

[G69]

Right- I'm learning... I was at Hershey Saturday and practiced keeping my mouth shut when viewing some pretty hairy modifications.

But back on track- Does anyone know what this mystery hole is? Experts at Hershey said it might be from an aftermarket Alarm System.
I do not have an engine compartment light and I'm told it is not automatically illuminated like the front trunk so no switch from factory.

I have seen this same hole on several different cars and always in the very same spot.

I'm having some work done in that corner so I want to know if I should have it welded-up and finished.
I'm leaning toward having it closed up since I see so many 1969 cars without it and it is just another distraction and source of corrosion.

What do you think?