I've been using 15mm rears from dsx-customs (
https://www.ebay.com/str/dsxcustoms) for the past 10 years with no issues...I just ordered a new pair as the F90 ones (5x120) don't work on the new G20 (5x112)...they stick to the hub ( I like they only have 5 holes) and stay secure on the lip...very good quality and as a bonus a bit cheaper the others...
Also, as a personal choice I use 15mm on the rears with no spacers up front...I find it gives the car a more aggressive look and also eliminates (potential) vibration issues...on my wife's Audi I had no choice but to put F/R as it's 4x4 - but then she doesn't abuse the car as much
