I've done one or two of these bumper films, and if there's one suggestion I could make it would be to get it as wet as you can, and keep it that way until you're happy that it's in the right place and all the bubbles are out.
There isn't enough stuff in the dinky little spray bottle that Audi provide. Not by a long way.
Fill a clean trigger spray bottle (like the kind window cleaner comes in) with warm water and add a couple of drops of washing up liquid. No more than that, otherwise it'll be all bubbles when you shake it up. The washing up liquid is there to break the surface tension of the water so that it sheets and spreads instead of beading.
Spray the bumper as well as both sides of the film with copious amounts of the mixture before lowering the film onto the bumper, making sure that the paintwork is scrupulously clean first.
You're aiming to get everything so wet that given half the chance the film will slip straight off again by itself. It needs to be this way so that you can slide it into its final position without having to lift it and re-wet it and before starting to work the water out from underneath with the squeegee.
If you need to peel it off to relocate it at any time, you didn't use enough water in the first place.
I didn't use the supplied squeegee. I don't doubt that it's a very good thing, but its edge is a little bit hard and unforgiving and will grab the film and stretch it if you happen to catch a bit without quite enough water on.
I used a square of plastic about the same size as the squeegee but a bit thinner (so it was more flexible), and gaffer-taped a small piece of double-folded soft cotton cloth - a bit of one of Mrs P's worn-out Victoria's Secrets, I think - over the edge. That worked well. The cloth makes the edge softer, and obviously it gets wet and stays that way, helping to maintain the lubrication.
If you excuse the expression.
I'm trying to avoid the smutty analogies, but it isn't really possible so I'll just say it anyway.
Get it all as wet as you can, and keep it wet. If it looks as if it's beginning to dry out at all, stop and make it wetter.
There is no such thing as too wet. Honestly. The worst that'll happen is that you might get a few drips on your shoes.
Take your time, and don't press too hard...
Good luck.
.