My brother has 20x8.5 with +42 offset (terrible) on his RS4, when they were first fitte they rubbed on the coilovers pretty bad, we have since fitted 25mm spacers from just jap to bring the final offset to +17.
I would think for 19x9 +35 down would be fine, depending on the type of suspension adjustment you are using, (coilovers the seat hight changes, this is what causes the rim/tyre to touch the suspension)
Not sure if this answers your question, but hopefully it helps.