The gasket can easily be missed on the stock downpipe. Sometimes it seats itself in far enough down that you would think it is actually just part of it. Either way, you should use one to help keep the exhaust gases where they belong. Even if you don't smell the fumes, you might be breathing it all in every time you come to a stop.
Edit: I don't remember if the gasket got stuck on the turbo side or DP side when I did my downpipe last year, but I initially missed it and went back looking for it because i knew there should be one there.
Now that I think of it, I remember having to use a small screw driver to remove the gasket from the turbo side of my MK6 when installing a DP. It was wedged in there pretty good due to the high temps on the turbo.
Good call. Switched out the DP last night (getting efficient, was about 45m-1 hr) and noticed the stock gasket was deep into the turbo collar. It's there, just squished. Have a slight leak reusing it, looks like I will have to buy another.
Thanks everyone!
Further info:
Called dealer - referral block on the gasket, need VIN to order. Seems to look like VW wants to know who is replacing exhaust parts so maybe they can flag in the system?
I searched part number provided above and found for $11 on amazon.
I am in the Great White North.
LOL. We have Amazon Canada!
Suppliers for VW auto parts are scarce though. I did find the part through german OEM though (Canadian supplier). Cheaper than the US too! only 7.50 in monopoly money.