so I bought a konig lace wheels that are 17x7 4x100/4x108 and the tire places tells me that i need a hub centric rings. I found some at Ebay but are they reliable? and what size should I get? and where else should I get them if ebay's rings are not recommended?

I drive an 08 R56 ~ my treads are gone and I need to change my tires asap. xD

 

Call the rim maker....they can tell you what the size of the center hub hole on the rim is....then they will look up you current car...and tell you what you need....the adaptor will be the plastic or metal ringy that makes up the difference...most better rim shops, some tire places have the same database....you CAN MEASURE if you are accurate...