I believe that for this style of spacer, the spacer bolts to the existing studs. The spacer then has it's own studs that the wheel would mount to. Here's a video that provides a good explanation:
I think the minimum width spacer you could use with the OEM studs is 5mm.
Right, I dont want to change out the original studs to longer ones, and I think just adding a plate spacer like 5mm which can use the original studs isnt enough to get a better look.
So I want a spacer to bolt to the hub using the original studs like the OP did, but not sure if its possible in a 20mm or 15mm version, because the nuts used to fasten the spacer to the original studs have a certain thickness, and it may be 30mm, so thats the thinnest you can go with this type of spacer. Just wonder if anyone knew the thinnest space with the integrates studs could be.
Sometimes an OEM wheel has "pockets" between the lug holes that would provide space for the OEM studs and lugs when using a spacer thinner than 30mm. See below:
I don't remember if the OEM wheels have these "pockets" or not, but I can check my winter set when I get home and get back to you.
Its a no brand set from Amazon, that appears to be a good quality!
4pieces 30mm Hub Centric Wheel Spacers | 5x114.3 5x4.5"| 1.18" Inch Thick https://www.amazon.com/dp/B06XQW6J9S/?tag=m20b7-20