you mite be able to make them work but you would have to see if you can have a min of 5mm milled off the back pad. to make them a et25 but depending on how low you want to go you would have to really strech your tires like a 195/45 hell even 195/40
to make it work and roll your fenders
yeah, I planned on stretching the hell out of the tires and if I had to, I would roll.
On a side note: that offset calc you posted had the hub to fender distance at 77mm...
I physically measured and came up with approx 85mm, that being the case, 20et would put it right at the fender.
I do appreciate your help here...new cars are always hard to figure measurements out.