ET for 17" wheel question

[kaitracid]

Can you please help me with an information: I need to know what J and ET I can put on a 17" wheel. This information is on a conformity certificate I think and I don't have it. I would like to know what is the minimum ET for the wheel...
Thank you!

 

[kaitracid]

I see that most of A3 wheels have ET50 and ET54. Is it ok to put wheels with ET40, ET 43, ET45? Like some models made for the A4...the 5 spoke S-line?

 

[FranA3]

i have got et45 wheels on mine but they are 18" s-line reps dont know if thats any help but they sit in the arches lovely