I'm in the process of fitting a boost gauge in my 300tdi. Searching the web it was suggested that taking the reading from the rear of the plenum chamber as LR had kindly left an opening there for this type of thing.

Anyway, I've done the interior part and I'm now moving onto the boost pipe. Bought the M12 x 1.5 Banjo bolt but I'm not sure it's the proper part.

Anyone done this who can tell me? Part I bought below.

I think a lot of people who do this just have a push connector and don't bother with the banjo thing you have pictured. But I can't see why this wouldn't work.

And I had to google plenum chamber. Plenum chamber - inlet manifold? Learn something new every day!