Reducing Drafts and fumes entering floor

[Steve Bryant]

While working on the new floor pan and checking clearances with the engine, gearbox and pedals, I noticed all the areas that fumes and drafts from the underside and engine bay could enter the interior of the car.  Pedals, accelerator, hole in firewall right behind the rear core plug of the engine, not to mention the gap around the engine and gear box itself.

Is there a favored way to seal these up so that this issue can be resolved in some way ...or is this part of the "joy"  of the A7 driving experience ;-)
Suggestions please.
Thanks,
Stephen