Incandescent bulbs at AUY

Hello and a beautiful second Advent to the forum!

I would like to have the bulbs checked in my Alhambra (AUY) sometime, as I suspect that one of them is not functioning correctly.

Just one silly question: I took a quick look under the hood today, but didn't find anything at first (I of course removed the cover and insulation). Where are the glow plugs located at the AUY (presumably referring to the engine compartment)? Or, how do I get to them? In my Skoda (ASV), I was able to see them without any problems. Maybe I just had tomatoes in my eyes.

I would be grateful for any tips or images. The valve head cover (the plastic part) doesn't necessarily have to be removed, does it?

Greetings

Dirk