You have to be careful using bolt on adapters as the combined offset can play havoc with the scrub radius effecting handling and too much offset can cause rubbing and premature wear on the suspension components as well as increases unsprung weight, in most cases they are a band aid, not a cure.
They are not the same as quality spacers that use a longer stud and steel hubs.
Best to get wheels that are 4x108 or do the 4x100 conversion and the proper offset or as close as you get to it.