No ET is given in the description. If youve won them then they should be ok i imagine, most RS6 reps are ET4? so arch fouling wont be the problem, just suspension distance. Tyre choice, size 225 or 235 most likely, but again different tyres have different shaped shoulders, some slope some are steep etc. Best way is trial fitting and taking some measurements if you still cant find the ET when you collect them.