I'm trying to figure out what the two bottom crush washers (in this picture below) are for that came in the fuel pump o ring kit. I know the two at the top of the picture is for the banjo bolt but not sure about the other two?
http://forum.a8parts.co.uk/attachmen...1&d=1604962593

Those will probably be for the night heater option - that uses a tiny banjo fitting on top of the long pump retaining bolt.

What is the night heater option?

A fuel-powered auxiliary heater which can warm up the car without the engine running. It lives under the air filter box and is plumbed in to the engine coolant circuit. It could be run on a timer or remote control so the car is toasty warm and defrosted on winter mornings.

Sounds like a nice feature! Is that able to be retrofitted to a car that didn't have it originally?

Anything can be retrofitted if you have a complete donor car. A friend in Germany is doing just that, but its a lot of work.

Aftermarket options are available though which is probably an easier option: https://www.webasto-comfort.com/en-i...arking-heater/