Here's my '06 Octavia vRS with 18x8.5 with staggered offsets, front two being ET45 and rear two ET40. Stock suspension, no spacers.
Granted it's not a MK5 but should be of similar fitment.
With ET40 at the front expect it to stick out as much if not more than mine does, as ET45 was chosen for the front in order to make it stick out less (obviously I underestimated how much it would
)
As you can see the front sticks out just ~10mm, whereas the back is just barely within the arch.
Also here's a picture taken at a slightly wider angle, so unless looking directly down the side of the car it's hard to tell it sticks out:
(also you can tell the rear doesn't stick out as much due to the rear having more camber than the front's).
Cheers, hope that helps
edit: This is with 225/40s
