Is something missing?

[CliffA4]

Hi there, I'm wondering if something is missing from the bottom of my gearbox. It's an A4 B5 1.8t 5 speed manual quattro. I've never noticed the shiny part in the picture below.

Also when I removed my undertray this hex socket bolt was sitting on it, does anyone know where it could be from? When I had the larger turbo installed by a mechanic he couldn't use the stock turbo bracket that supports the turbo, could he have put this bolt in loose and it's just fallen out or is it from somewhere else. I've looked around with a light and can't see where it may have come from, please help.

 

[NHN]

Well given it's size, it looks like a fixing bolt for something to hold in place, he probably dropped it when working on the car & it's trickled down now.

Looks familiar to other likewise bolts I've worked with.

 

[CliffA4]

Well given it's size, it looks like a fixing bolt for something to hold in place, he probably dropped it when working on the car & it's trickled down now.

Looks familiar to other likewise bolts I've worked with.

Thankyou for the reply, I'm hoping it's just one of the unused turbo bracket bolts. It was done a few months back and I've had the tray off a few times so he may have lightly put it back in and not tightened it.
What about the bottom of the gearbox are you familiar with them? It looks like something is missing, I've never noticed the clean part in the picture.