Yes I see the spacer. Here's the thing; the hub is around 8mm thick and the thickest spacer that can be used is 3mm (1/8") to keep it hub centric. Many wheels that are really close to the caliper only require a 3mm spacer. There's only one place I know of that makes a 3mm aluminum 6x139.7 - 78.1 bore spacer. So then, with the 8mm hub thickness and using a 1/4" or 6mm spacer that you have, that only leaves you 2mm of hub left and with the hub end taper and wheel bore taper, there's just not enough meat on the bone to grab the hub and keep the wheel hub centric.