As far as the trim rings fitting tight to the rim I believe they are supposed to stand off a little to accommodate wheel weights used in the wheel balancing process. If not you would run the risk of the trim ring not being seated properly and possibly flying off creating havic. I also believe people keep trying to beat them on until flush with no success resulting in a lot of very badly dented trim rings for sale at swap meets and making the aftermarket parts owners lots of money. Just my rant on this subject, you may disagree.