I currently use 3x112 to 5x112 wheel adapters. Those are supposed to be the safest as they line up with one of the holes or something like that. Im not too sure of the science on it but if you do 5x112 you can use mercedes wheels anyways so it works out. I got mine on ebay from a company in redlands california because I live close and I know theyre american made. After ordering an air intake and stuff from smart madness and being told wait time was nearly two months I decided to buy my wheel adapters elsewhere. But even if you decide to go with smartmadness I recommend using the 3x112 to 5x112 adapters. My instagram is lordpaige, there you will see my original brabus wheels on the smart, a set of 18x8 tsw wheels on it and my most current set of 16x8 Lorinser rs90 wheels. If you have any questions reply back or message me on instagram. The company sells them on ebay but if you have your eyes set on a 4 lug rim they do make a 3x112 to 4x100 adapter.